Scuba Diving
256 Pages
The best-selling authoritative resource returns updated and better than ever.
Scuba Diving, Fifth Edition, is the most up-to-date resource for experiencing secure, satisfying dives. Packed with full-color photographs and detailed diving instruction, this is the ideal companion for recreational divers, diving instructors, and students.
Veteran instructor Dennis Graver shares the latest research, science, and recommendations as well as nearly 40 years of diving experience. He demystifies complex topics such as gas laws and the physics and physiology of scuba. You’ll also learn these skills:
• Equalize pressure in the sinuses, ears, and mask.
• Follow boat diving and buddy check procedures.
• Master the nuances of dive planning and decompression so that every dive is safe and enjoyable.
• Choose, use, and maintain scuba equipment.
• Safely enjoy the underwater environment, including aquatic wildlife.
• Prevent or manage underwater emergencies and hazards.
In this new edition you’ll find Application of Knowledge (AOK) questions and answers. For the first time, you’ll be able to apply the information and guidelines to real-world scuba problems, making you better prepared for those unexpected situations you might encounter.
Whether you are a beginning or intermediate diver or diving instructor, make sure you have all the bases covered before you go underwater. Scuba Diving will ensure a safe, successful, and rewarding dive every time you take the plunge.
Chapter 1 Diving Into Scuba
Chapter 2 Diving Science
Chapter 3 Diving Adjustments
Chapter 4 Diving Equipment
Chapter 5 Diving Environment
Chapter 6 Diving Skills
Chapter 7 Dive Planning
Chapter 8 Diving Opportunities
Dennis Graver has been a scuba instructor and instructor trainer since 1968. He has written 27 books and manuals on the subject, including four previous editions of Scuba Diving published by Human Kinetics. As director of training for the Professional Association of Diving Instructors (PADI), he designed the PADI modular scuba course and wrote the PADI Dive Manual, which revolutionized scuba instruction. During his tenure as director of education for the National Association of Underwater Instructors (NAUI), Graver wrote several diving texts and manuals, including the NAUI Open Water I Scuba Diver Course Instructor Guide. He has contributed hundreds of articles on diving to magazines such as Skin Diver, Sources, and Undercurrents as well as several NAUI technical publications.
Merging twin passions, Graver has expertly photographed many wonders under the water from the Red Sea off the coast of Egypt to the barrier reefs of Australia. He has won numerous awards from the Underwater Photographic Society, and his photos have graced the covers of numerous magazines and illustrated several diving texts and audiovisual educational programs.
Graver and his wife, Barbara, live in Camano Island, Washington.
Buoyancy
An object’s ability to float in a liquid depends on the density of the object compared with the density of the fluid in which the object is immersed. Water exerts pressure equally in all directions, even upward. You can feel the upward force (buoyancy) of water when you try to push something under the water.
An object's ability to float in a liquid depends on the density of the object compared with the density of the fluid in which the object is immersed. Water exerts pressure equally in all directions, even upward. You can feel the upward force (buoyancy) of water when you try to push something under the water. Buoyancy results from the difference in pressures on the upper and lower surfaces of an object. The weight of an object plus the weight of the fluid (air, water, or both) above the object exert a downward force. Fluid pressure pushes upward from below. The difference between these two forces is the buoyancy of the object.
Archimedes, an ancient Greek scientist, discovered that the force of buoyancy acting on a submerged object equals the weight of the water displaced (this is known as Archimedes' principle). A hot-air balloon floats in air because the hot air inside the balloon weighs less than the volume of cooler air the balloon occupies. A diver is buoyed upward with a force equal to the weight of the water that the diver displaces (see figure 2.8). If you and your equipment weigh less than the weight of the water you displace, you will float, or have positive buoyancy. If you and your equipment weigh more than the water being displaced, you will sink. An object that sinks has negative buoyancy. If you and your equipment weigh exactly the same as the water displaced, you neither float nor sink. Instead, you remain at the depth where you are; you have neutral buoyancy.
Principles of buoyancy.
Learn more about Scuba Diving, Fifth Edition.
Using Scuba Diving Hand Signals
Scuba divers use several hand signals that are not used for skin diving. The signals specific to scuba diving relate to air supply.
Scuba divers use several hand signals that are not used for skin diving. The signals specific to scuba diving relate to air supply. Learn and use the standard hand signals shown below. Remember to display hand signals clearly and deliberately and also to acknowledge the hand signals you receive.
Scuba diving hand signals.
Save
Learn more about Scuba Diving, Fifth Edition.
Dive-Planning Factors
Many factors affect your plans for a dive or a diving trip. Keep the following considerations in mind when you are looking ahead to a dive outing.
Many factors affect your plans for a dive or a diving trip. Keep the following considerations in mind when you are looking ahead to a dive outing:
- Health and fitness are important. Illnesses, required medications, and recent operations probably disqualify you for diving. If your health is not normal, consult a diving physician. If there is any doubt about your physical condition, refrain from diving until you are in good health. If you are prone to motion sickness, take steps to try to prevent it.
- Climate is a big factor affecting dive planning. If you dive close to where you live, dive planning is easier than if you intend to dive thousands of miles away. A difference in climate usually means a big difference in diving conditions, which means a difference in your equipment requirements.
- The distance you travel to a diving destination affects your planning. If you travel far to reach the destination, allow a day to rest and recover from travel before you dive. After even one day of repetitive diving, wait one full day before flying home.
- Weather affects diving conditions significantly. Storms and sudden changes in the weather can make diving dangerous. Know the weather forecast, and reschedule your dive if poor weather is predicted. Know the expected wind speed, air temperature, and water conditions.
- Seasonal changes affect water movement, water visibility, air and water temperatures, entry and exit areas, and the presence of certain types of animals. You should know what to expect at a dive site at different times of the year. It helps to know the visibility, water temperatures, tides, surf, surge, currents, bottom composition, silt conditions, plants, and animals.
You need to be physically and mentally fit for diving. Fitness for diving implies that you are well rested, are well nourished, have the physical strength and stamina to meet the requirements of the environment and the activity, are qualified for the activity, are not apprehensive about your plans, are not goaded into doing something you are not prepared to do, and do not allow pride to affect good judgment.
Your objective for the dive affects your planning. Different diving activities require different plans and different equipment. The planning of an underwater photography dive is not the same as the planning of a dive where you intend to hunt for game.
You must know and observe laws, regulations, and customs. Some areas have laws that require the use of a dive flag. Obey fish and game regulations. Some diving professionals discourage the taking of any living thing in an area. You need to know the behavior expected of you. Knowing the expectations in advance can help you avoid being embarrassed at the dive site.
Etiquette is important. Will early-morning diving activities be offensive to residents near the dive site? Will the parking of vehicles at a site irritate people? Be considerate of others who may be in the area where you intend to dive, including those who are fishing nearby. Consider the impact of noise, changing clothes, and dive site access. Then make your plans using good etiquette.
Save
Learn more about Scuba Diving, Fifth Edition.
Selecting a Dive Course
There are many diver training organizations and thousands of professional diving educators. Your phone book might list diving businesses that offer sanctioned courses. Many universities, community colleges, and recreational departments also offer scuba courses.
There are many diver training organizations and thousands of professional diving educators. Your phone book might list diving businesses that offer sanctioned courses. Many universities, community colleges, and recreational departments also offer scuba courses. (See Appendix A for a list of diver training organizations.) Ask about the qualifications, experience, and reputation of several diving instructors in your area to select the course that can provide you with the best possible training. Here are some questions you should ask:
- Is this training sanctioned by a diver training agency?
- How long has the instructor been teaching scuba diving?
- Which levels of training is the instructor qualified to teach?
- May I speak with the graduates of a recent class?
- Why is this course better than others in the area?
- Are assisting and rescue techniques taught in the course?
- How many instructor-supervised open-water dives are included?
The tuition for diving instruction is usually between $200 and $300. The lowest-priced course may not necessarily be a bargain. Find out what is included with the course fee and, more important, what the total cost will be for you to become certified as a scuba diver. You do not have to purchase all the equipment needed to scuba dive, but you need to have a mask, snorkel, fins, and usually boots and gloves for your training (see figure 1.1). Use of the additional required equipment is typically part of the course tuition.
Required scuba diving training equipment.
You should find out whether the price of the course includes the costs of educational materials and certification. There may be additional costs for travel, lodging, parking, boat fees, and equipment rental for open-water training. Determine the complete cost before enrolling in a course.
When you have selected the best program for you and have enrolled in a course, you should receive a reading assignment for your first session. If you are not given an assignment, speak with the instructor; your learning will be enhanced if you read in advance about the topics to be presented in class. Good diving instructors provide a handout with reading assignments.
Learn more about Scuba Diving, Fifth Edition.
Buoyancy
An object’s ability to float in a liquid depends on the density of the object compared with the density of the fluid in which the object is immersed. Water exerts pressure equally in all directions, even upward. You can feel the upward force (buoyancy) of water when you try to push something under the water.
An object's ability to float in a liquid depends on the density of the object compared with the density of the fluid in which the object is immersed. Water exerts pressure equally in all directions, even upward. You can feel the upward force (buoyancy) of water when you try to push something under the water. Buoyancy results from the difference in pressures on the upper and lower surfaces of an object. The weight of an object plus the weight of the fluid (air, water, or both) above the object exert a downward force. Fluid pressure pushes upward from below. The difference between these two forces is the buoyancy of the object.
Archimedes, an ancient Greek scientist, discovered that the force of buoyancy acting on a submerged object equals the weight of the water displaced (this is known as Archimedes' principle). A hot-air balloon floats in air because the hot air inside the balloon weighs less than the volume of cooler air the balloon occupies. A diver is buoyed upward with a force equal to the weight of the water that the diver displaces (see figure 2.8). If you and your equipment weigh less than the weight of the water you displace, you will float, or have positive buoyancy. If you and your equipment weigh more than the water being displaced, you will sink. An object that sinks has negative buoyancy. If you and your equipment weigh exactly the same as the water displaced, you neither float nor sink. Instead, you remain at the depth where you are; you have neutral buoyancy.
Principles of buoyancy.
Learn more about Scuba Diving, Fifth Edition.
Using Scuba Diving Hand Signals
Scuba divers use several hand signals that are not used for skin diving. The signals specific to scuba diving relate to air supply.
Scuba divers use several hand signals that are not used for skin diving. The signals specific to scuba diving relate to air supply. Learn and use the standard hand signals shown below. Remember to display hand signals clearly and deliberately and also to acknowledge the hand signals you receive.
Scuba diving hand signals.
Save
Learn more about Scuba Diving, Fifth Edition.
Dive-Planning Factors
Many factors affect your plans for a dive or a diving trip. Keep the following considerations in mind when you are looking ahead to a dive outing.
Many factors affect your plans for a dive or a diving trip. Keep the following considerations in mind when you are looking ahead to a dive outing:
- Health and fitness are important. Illnesses, required medications, and recent operations probably disqualify you for diving. If your health is not normal, consult a diving physician. If there is any doubt about your physical condition, refrain from diving until you are in good health. If you are prone to motion sickness, take steps to try to prevent it.
- Climate is a big factor affecting dive planning. If you dive close to where you live, dive planning is easier than if you intend to dive thousands of miles away. A difference in climate usually means a big difference in diving conditions, which means a difference in your equipment requirements.
- The distance you travel to a diving destination affects your planning. If you travel far to reach the destination, allow a day to rest and recover from travel before you dive. After even one day of repetitive diving, wait one full day before flying home.
- Weather affects diving conditions significantly. Storms and sudden changes in the weather can make diving dangerous. Know the weather forecast, and reschedule your dive if poor weather is predicted. Know the expected wind speed, air temperature, and water conditions.
- Seasonal changes affect water movement, water visibility, air and water temperatures, entry and exit areas, and the presence of certain types of animals. You should know what to expect at a dive site at different times of the year. It helps to know the visibility, water temperatures, tides, surf, surge, currents, bottom composition, silt conditions, plants, and animals.
You need to be physically and mentally fit for diving. Fitness for diving implies that you are well rested, are well nourished, have the physical strength and stamina to meet the requirements of the environment and the activity, are qualified for the activity, are not apprehensive about your plans, are not goaded into doing something you are not prepared to do, and do not allow pride to affect good judgment.
Your objective for the dive affects your planning. Different diving activities require different plans and different equipment. The planning of an underwater photography dive is not the same as the planning of a dive where you intend to hunt for game.
You must know and observe laws, regulations, and customs. Some areas have laws that require the use of a dive flag. Obey fish and game regulations. Some diving professionals discourage the taking of any living thing in an area. You need to know the behavior expected of you. Knowing the expectations in advance can help you avoid being embarrassed at the dive site.
Etiquette is important. Will early-morning diving activities be offensive to residents near the dive site? Will the parking of vehicles at a site irritate people? Be considerate of others who may be in the area where you intend to dive, including those who are fishing nearby. Consider the impact of noise, changing clothes, and dive site access. Then make your plans using good etiquette.
Save
Learn more about Scuba Diving, Fifth Edition.
Selecting a Dive Course
There are many diver training organizations and thousands of professional diving educators. Your phone book might list diving businesses that offer sanctioned courses. Many universities, community colleges, and recreational departments also offer scuba courses.
There are many diver training organizations and thousands of professional diving educators. Your phone book might list diving businesses that offer sanctioned courses. Many universities, community colleges, and recreational departments also offer scuba courses. (See Appendix A for a list of diver training organizations.) Ask about the qualifications, experience, and reputation of several diving instructors in your area to select the course that can provide you with the best possible training. Here are some questions you should ask:
- Is this training sanctioned by a diver training agency?
- How long has the instructor been teaching scuba diving?
- Which levels of training is the instructor qualified to teach?
- May I speak with the graduates of a recent class?
- Why is this course better than others in the area?
- Are assisting and rescue techniques taught in the course?
- How many instructor-supervised open-water dives are included?
The tuition for diving instruction is usually between $200 and $300. The lowest-priced course may not necessarily be a bargain. Find out what is included with the course fee and, more important, what the total cost will be for you to become certified as a scuba diver. You do not have to purchase all the equipment needed to scuba dive, but you need to have a mask, snorkel, fins, and usually boots and gloves for your training (see figure 1.1). Use of the additional required equipment is typically part of the course tuition.
Required scuba diving training equipment.
You should find out whether the price of the course includes the costs of educational materials and certification. There may be additional costs for travel, lodging, parking, boat fees, and equipment rental for open-water training. Determine the complete cost before enrolling in a course.
When you have selected the best program for you and have enrolled in a course, you should receive a reading assignment for your first session. If you are not given an assignment, speak with the instructor; your learning will be enhanced if you read in advance about the topics to be presented in class. Good diving instructors provide a handout with reading assignments.
Learn more about Scuba Diving, Fifth Edition.
Buoyancy
An object’s ability to float in a liquid depends on the density of the object compared with the density of the fluid in which the object is immersed. Water exerts pressure equally in all directions, even upward. You can feel the upward force (buoyancy) of water when you try to push something under the water.
An object's ability to float in a liquid depends on the density of the object compared with the density of the fluid in which the object is immersed. Water exerts pressure equally in all directions, even upward. You can feel the upward force (buoyancy) of water when you try to push something under the water. Buoyancy results from the difference in pressures on the upper and lower surfaces of an object. The weight of an object plus the weight of the fluid (air, water, or both) above the object exert a downward force. Fluid pressure pushes upward from below. The difference between these two forces is the buoyancy of the object.
Archimedes, an ancient Greek scientist, discovered that the force of buoyancy acting on a submerged object equals the weight of the water displaced (this is known as Archimedes' principle). A hot-air balloon floats in air because the hot air inside the balloon weighs less than the volume of cooler air the balloon occupies. A diver is buoyed upward with a force equal to the weight of the water that the diver displaces (see figure 2.8). If you and your equipment weigh less than the weight of the water you displace, you will float, or have positive buoyancy. If you and your equipment weigh more than the water being displaced, you will sink. An object that sinks has negative buoyancy. If you and your equipment weigh exactly the same as the water displaced, you neither float nor sink. Instead, you remain at the depth where you are; you have neutral buoyancy.
Principles of buoyancy.
Learn more about Scuba Diving, Fifth Edition.
Using Scuba Diving Hand Signals
Scuba divers use several hand signals that are not used for skin diving. The signals specific to scuba diving relate to air supply.
Scuba divers use several hand signals that are not used for skin diving. The signals specific to scuba diving relate to air supply. Learn and use the standard hand signals shown below. Remember to display hand signals clearly and deliberately and also to acknowledge the hand signals you receive.
Scuba diving hand signals.
Save
Learn more about Scuba Diving, Fifth Edition.
Dive-Planning Factors
Many factors affect your plans for a dive or a diving trip. Keep the following considerations in mind when you are looking ahead to a dive outing.
Many factors affect your plans for a dive or a diving trip. Keep the following considerations in mind when you are looking ahead to a dive outing:
- Health and fitness are important. Illnesses, required medications, and recent operations probably disqualify you for diving. If your health is not normal, consult a diving physician. If there is any doubt about your physical condition, refrain from diving until you are in good health. If you are prone to motion sickness, take steps to try to prevent it.
- Climate is a big factor affecting dive planning. If you dive close to where you live, dive planning is easier than if you intend to dive thousands of miles away. A difference in climate usually means a big difference in diving conditions, which means a difference in your equipment requirements.
- The distance you travel to a diving destination affects your planning. If you travel far to reach the destination, allow a day to rest and recover from travel before you dive. After even one day of repetitive diving, wait one full day before flying home.
- Weather affects diving conditions significantly. Storms and sudden changes in the weather can make diving dangerous. Know the weather forecast, and reschedule your dive if poor weather is predicted. Know the expected wind speed, air temperature, and water conditions.
- Seasonal changes affect water movement, water visibility, air and water temperatures, entry and exit areas, and the presence of certain types of animals. You should know what to expect at a dive site at different times of the year. It helps to know the visibility, water temperatures, tides, surf, surge, currents, bottom composition, silt conditions, plants, and animals.
You need to be physically and mentally fit for diving. Fitness for diving implies that you are well rested, are well nourished, have the physical strength and stamina to meet the requirements of the environment and the activity, are qualified for the activity, are not apprehensive about your plans, are not goaded into doing something you are not prepared to do, and do not allow pride to affect good judgment.
Your objective for the dive affects your planning. Different diving activities require different plans and different equipment. The planning of an underwater photography dive is not the same as the planning of a dive where you intend to hunt for game.
You must know and observe laws, regulations, and customs. Some areas have laws that require the use of a dive flag. Obey fish and game regulations. Some diving professionals discourage the taking of any living thing in an area. You need to know the behavior expected of you. Knowing the expectations in advance can help you avoid being embarrassed at the dive site.
Etiquette is important. Will early-morning diving activities be offensive to residents near the dive site? Will the parking of vehicles at a site irritate people? Be considerate of others who may be in the area where you intend to dive, including those who are fishing nearby. Consider the impact of noise, changing clothes, and dive site access. Then make your plans using good etiquette.
Save
Learn more about Scuba Diving, Fifth Edition.
Selecting a Dive Course
There are many diver training organizations and thousands of professional diving educators. Your phone book might list diving businesses that offer sanctioned courses. Many universities, community colleges, and recreational departments also offer scuba courses.
There are many diver training organizations and thousands of professional diving educators. Your phone book might list diving businesses that offer sanctioned courses. Many universities, community colleges, and recreational departments also offer scuba courses. (See Appendix A for a list of diver training organizations.) Ask about the qualifications, experience, and reputation of several diving instructors in your area to select the course that can provide you with the best possible training. Here are some questions you should ask:
- Is this training sanctioned by a diver training agency?
- How long has the instructor been teaching scuba diving?
- Which levels of training is the instructor qualified to teach?
- May I speak with the graduates of a recent class?
- Why is this course better than others in the area?
- Are assisting and rescue techniques taught in the course?
- How many instructor-supervised open-water dives are included?
The tuition for diving instruction is usually between $200 and $300. The lowest-priced course may not necessarily be a bargain. Find out what is included with the course fee and, more important, what the total cost will be for you to become certified as a scuba diver. You do not have to purchase all the equipment needed to scuba dive, but you need to have a mask, snorkel, fins, and usually boots and gloves for your training (see figure 1.1). Use of the additional required equipment is typically part of the course tuition.
Required scuba diving training equipment.
You should find out whether the price of the course includes the costs of educational materials and certification. There may be additional costs for travel, lodging, parking, boat fees, and equipment rental for open-water training. Determine the complete cost before enrolling in a course.
When you have selected the best program for you and have enrolled in a course, you should receive a reading assignment for your first session. If you are not given an assignment, speak with the instructor; your learning will be enhanced if you read in advance about the topics to be presented in class. Good diving instructors provide a handout with reading assignments.
Learn more about Scuba Diving, Fifth Edition.
Buoyancy
An object’s ability to float in a liquid depends on the density of the object compared with the density of the fluid in which the object is immersed. Water exerts pressure equally in all directions, even upward. You can feel the upward force (buoyancy) of water when you try to push something under the water.
An object's ability to float in a liquid depends on the density of the object compared with the density of the fluid in which the object is immersed. Water exerts pressure equally in all directions, even upward. You can feel the upward force (buoyancy) of water when you try to push something under the water. Buoyancy results from the difference in pressures on the upper and lower surfaces of an object. The weight of an object plus the weight of the fluid (air, water, or both) above the object exert a downward force. Fluid pressure pushes upward from below. The difference between these two forces is the buoyancy of the object.
Archimedes, an ancient Greek scientist, discovered that the force of buoyancy acting on a submerged object equals the weight of the water displaced (this is known as Archimedes' principle). A hot-air balloon floats in air because the hot air inside the balloon weighs less than the volume of cooler air the balloon occupies. A diver is buoyed upward with a force equal to the weight of the water that the diver displaces (see figure 2.8). If you and your equipment weigh less than the weight of the water you displace, you will float, or have positive buoyancy. If you and your equipment weigh more than the water being displaced, you will sink. An object that sinks has negative buoyancy. If you and your equipment weigh exactly the same as the water displaced, you neither float nor sink. Instead, you remain at the depth where you are; you have neutral buoyancy.
Principles of buoyancy.
Learn more about Scuba Diving, Fifth Edition.
Using Scuba Diving Hand Signals
Scuba divers use several hand signals that are not used for skin diving. The signals specific to scuba diving relate to air supply.
Scuba divers use several hand signals that are not used for skin diving. The signals specific to scuba diving relate to air supply. Learn and use the standard hand signals shown below. Remember to display hand signals clearly and deliberately and also to acknowledge the hand signals you receive.
Scuba diving hand signals.
Save
Learn more about Scuba Diving, Fifth Edition.
Dive-Planning Factors
Many factors affect your plans for a dive or a diving trip. Keep the following considerations in mind when you are looking ahead to a dive outing.
Many factors affect your plans for a dive or a diving trip. Keep the following considerations in mind when you are looking ahead to a dive outing:
- Health and fitness are important. Illnesses, required medications, and recent operations probably disqualify you for diving. If your health is not normal, consult a diving physician. If there is any doubt about your physical condition, refrain from diving until you are in good health. If you are prone to motion sickness, take steps to try to prevent it.
- Climate is a big factor affecting dive planning. If you dive close to where you live, dive planning is easier than if you intend to dive thousands of miles away. A difference in climate usually means a big difference in diving conditions, which means a difference in your equipment requirements.
- The distance you travel to a diving destination affects your planning. If you travel far to reach the destination, allow a day to rest and recover from travel before you dive. After even one day of repetitive diving, wait one full day before flying home.
- Weather affects diving conditions significantly. Storms and sudden changes in the weather can make diving dangerous. Know the weather forecast, and reschedule your dive if poor weather is predicted. Know the expected wind speed, air temperature, and water conditions.
- Seasonal changes affect water movement, water visibility, air and water temperatures, entry and exit areas, and the presence of certain types of animals. You should know what to expect at a dive site at different times of the year. It helps to know the visibility, water temperatures, tides, surf, surge, currents, bottom composition, silt conditions, plants, and animals.
You need to be physically and mentally fit for diving. Fitness for diving implies that you are well rested, are well nourished, have the physical strength and stamina to meet the requirements of the environment and the activity, are qualified for the activity, are not apprehensive about your plans, are not goaded into doing something you are not prepared to do, and do not allow pride to affect good judgment.
Your objective for the dive affects your planning. Different diving activities require different plans and different equipment. The planning of an underwater photography dive is not the same as the planning of a dive where you intend to hunt for game.
You must know and observe laws, regulations, and customs. Some areas have laws that require the use of a dive flag. Obey fish and game regulations. Some diving professionals discourage the taking of any living thing in an area. You need to know the behavior expected of you. Knowing the expectations in advance can help you avoid being embarrassed at the dive site.
Etiquette is important. Will early-morning diving activities be offensive to residents near the dive site? Will the parking of vehicles at a site irritate people? Be considerate of others who may be in the area where you intend to dive, including those who are fishing nearby. Consider the impact of noise, changing clothes, and dive site access. Then make your plans using good etiquette.
Save
Learn more about Scuba Diving, Fifth Edition.
Selecting a Dive Course
There are many diver training organizations and thousands of professional diving educators. Your phone book might list diving businesses that offer sanctioned courses. Many universities, community colleges, and recreational departments also offer scuba courses.
There are many diver training organizations and thousands of professional diving educators. Your phone book might list diving businesses that offer sanctioned courses. Many universities, community colleges, and recreational departments also offer scuba courses. (See Appendix A for a list of diver training organizations.) Ask about the qualifications, experience, and reputation of several diving instructors in your area to select the course that can provide you with the best possible training. Here are some questions you should ask:
- Is this training sanctioned by a diver training agency?
- How long has the instructor been teaching scuba diving?
- Which levels of training is the instructor qualified to teach?
- May I speak with the graduates of a recent class?
- Why is this course better than others in the area?
- Are assisting and rescue techniques taught in the course?
- How many instructor-supervised open-water dives are included?
The tuition for diving instruction is usually between $200 and $300. The lowest-priced course may not necessarily be a bargain. Find out what is included with the course fee and, more important, what the total cost will be for you to become certified as a scuba diver. You do not have to purchase all the equipment needed to scuba dive, but you need to have a mask, snorkel, fins, and usually boots and gloves for your training (see figure 1.1). Use of the additional required equipment is typically part of the course tuition.
Required scuba diving training equipment.
You should find out whether the price of the course includes the costs of educational materials and certification. There may be additional costs for travel, lodging, parking, boat fees, and equipment rental for open-water training. Determine the complete cost before enrolling in a course.
When you have selected the best program for you and have enrolled in a course, you should receive a reading assignment for your first session. If you are not given an assignment, speak with the instructor; your learning will be enhanced if you read in advance about the topics to be presented in class. Good diving instructors provide a handout with reading assignments.
Learn more about Scuba Diving, Fifth Edition.
Buoyancy
An object’s ability to float in a liquid depends on the density of the object compared with the density of the fluid in which the object is immersed. Water exerts pressure equally in all directions, even upward. You can feel the upward force (buoyancy) of water when you try to push something under the water.
An object's ability to float in a liquid depends on the density of the object compared with the density of the fluid in which the object is immersed. Water exerts pressure equally in all directions, even upward. You can feel the upward force (buoyancy) of water when you try to push something under the water. Buoyancy results from the difference in pressures on the upper and lower surfaces of an object. The weight of an object plus the weight of the fluid (air, water, or both) above the object exert a downward force. Fluid pressure pushes upward from below. The difference between these two forces is the buoyancy of the object.
Archimedes, an ancient Greek scientist, discovered that the force of buoyancy acting on a submerged object equals the weight of the water displaced (this is known as Archimedes' principle). A hot-air balloon floats in air because the hot air inside the balloon weighs less than the volume of cooler air the balloon occupies. A diver is buoyed upward with a force equal to the weight of the water that the diver displaces (see figure 2.8). If you and your equipment weigh less than the weight of the water you displace, you will float, or have positive buoyancy. If you and your equipment weigh more than the water being displaced, you will sink. An object that sinks has negative buoyancy. If you and your equipment weigh exactly the same as the water displaced, you neither float nor sink. Instead, you remain at the depth where you are; you have neutral buoyancy.
Principles of buoyancy.
Learn more about Scuba Diving, Fifth Edition.
Using Scuba Diving Hand Signals
Scuba divers use several hand signals that are not used for skin diving. The signals specific to scuba diving relate to air supply.
Scuba divers use several hand signals that are not used for skin diving. The signals specific to scuba diving relate to air supply. Learn and use the standard hand signals shown below. Remember to display hand signals clearly and deliberately and also to acknowledge the hand signals you receive.
Scuba diving hand signals.
Save
Learn more about Scuba Diving, Fifth Edition.
Dive-Planning Factors
Many factors affect your plans for a dive or a diving trip. Keep the following considerations in mind when you are looking ahead to a dive outing.
Many factors affect your plans for a dive or a diving trip. Keep the following considerations in mind when you are looking ahead to a dive outing:
- Health and fitness are important. Illnesses, required medications, and recent operations probably disqualify you for diving. If your health is not normal, consult a diving physician. If there is any doubt about your physical condition, refrain from diving until you are in good health. If you are prone to motion sickness, take steps to try to prevent it.
- Climate is a big factor affecting dive planning. If you dive close to where you live, dive planning is easier than if you intend to dive thousands of miles away. A difference in climate usually means a big difference in diving conditions, which means a difference in your equipment requirements.
- The distance you travel to a diving destination affects your planning. If you travel far to reach the destination, allow a day to rest and recover from travel before you dive. After even one day of repetitive diving, wait one full day before flying home.
- Weather affects diving conditions significantly. Storms and sudden changes in the weather can make diving dangerous. Know the weather forecast, and reschedule your dive if poor weather is predicted. Know the expected wind speed, air temperature, and water conditions.
- Seasonal changes affect water movement, water visibility, air and water temperatures, entry and exit areas, and the presence of certain types of animals. You should know what to expect at a dive site at different times of the year. It helps to know the visibility, water temperatures, tides, surf, surge, currents, bottom composition, silt conditions, plants, and animals.
You need to be physically and mentally fit for diving. Fitness for diving implies that you are well rested, are well nourished, have the physical strength and stamina to meet the requirements of the environment and the activity, are qualified for the activity, are not apprehensive about your plans, are not goaded into doing something you are not prepared to do, and do not allow pride to affect good judgment.
Your objective for the dive affects your planning. Different diving activities require different plans and different equipment. The planning of an underwater photography dive is not the same as the planning of a dive where you intend to hunt for game.
You must know and observe laws, regulations, and customs. Some areas have laws that require the use of a dive flag. Obey fish and game regulations. Some diving professionals discourage the taking of any living thing in an area. You need to know the behavior expected of you. Knowing the expectations in advance can help you avoid being embarrassed at the dive site.
Etiquette is important. Will early-morning diving activities be offensive to residents near the dive site? Will the parking of vehicles at a site irritate people? Be considerate of others who may be in the area where you intend to dive, including those who are fishing nearby. Consider the impact of noise, changing clothes, and dive site access. Then make your plans using good etiquette.
Save
Learn more about Scuba Diving, Fifth Edition.
Selecting a Dive Course
There are many diver training organizations and thousands of professional diving educators. Your phone book might list diving businesses that offer sanctioned courses. Many universities, community colleges, and recreational departments also offer scuba courses.
There are many diver training organizations and thousands of professional diving educators. Your phone book might list diving businesses that offer sanctioned courses. Many universities, community colleges, and recreational departments also offer scuba courses. (See Appendix A for a list of diver training organizations.) Ask about the qualifications, experience, and reputation of several diving instructors in your area to select the course that can provide you with the best possible training. Here are some questions you should ask:
- Is this training sanctioned by a diver training agency?
- How long has the instructor been teaching scuba diving?
- Which levels of training is the instructor qualified to teach?
- May I speak with the graduates of a recent class?
- Why is this course better than others in the area?
- Are assisting and rescue techniques taught in the course?
- How many instructor-supervised open-water dives are included?
The tuition for diving instruction is usually between $200 and $300. The lowest-priced course may not necessarily be a bargain. Find out what is included with the course fee and, more important, what the total cost will be for you to become certified as a scuba diver. You do not have to purchase all the equipment needed to scuba dive, but you need to have a mask, snorkel, fins, and usually boots and gloves for your training (see figure 1.1). Use of the additional required equipment is typically part of the course tuition.
Required scuba diving training equipment.
You should find out whether the price of the course includes the costs of educational materials and certification. There may be additional costs for travel, lodging, parking, boat fees, and equipment rental for open-water training. Determine the complete cost before enrolling in a course.
When you have selected the best program for you and have enrolled in a course, you should receive a reading assignment for your first session. If you are not given an assignment, speak with the instructor; your learning will be enhanced if you read in advance about the topics to be presented in class. Good diving instructors provide a handout with reading assignments.
Learn more about Scuba Diving, Fifth Edition.
Buoyancy
An object’s ability to float in a liquid depends on the density of the object compared with the density of the fluid in which the object is immersed. Water exerts pressure equally in all directions, even upward. You can feel the upward force (buoyancy) of water when you try to push something under the water.
An object's ability to float in a liquid depends on the density of the object compared with the density of the fluid in which the object is immersed. Water exerts pressure equally in all directions, even upward. You can feel the upward force (buoyancy) of water when you try to push something under the water. Buoyancy results from the difference in pressures on the upper and lower surfaces of an object. The weight of an object plus the weight of the fluid (air, water, or both) above the object exert a downward force. Fluid pressure pushes upward from below. The difference between these two forces is the buoyancy of the object.
Archimedes, an ancient Greek scientist, discovered that the force of buoyancy acting on a submerged object equals the weight of the water displaced (this is known as Archimedes' principle). A hot-air balloon floats in air because the hot air inside the balloon weighs less than the volume of cooler air the balloon occupies. A diver is buoyed upward with a force equal to the weight of the water that the diver displaces (see figure 2.8). If you and your equipment weigh less than the weight of the water you displace, you will float, or have positive buoyancy. If you and your equipment weigh more than the water being displaced, you will sink. An object that sinks has negative buoyancy. If you and your equipment weigh exactly the same as the water displaced, you neither float nor sink. Instead, you remain at the depth where you are; you have neutral buoyancy.
Principles of buoyancy.
Learn more about Scuba Diving, Fifth Edition.
Using Scuba Diving Hand Signals
Scuba divers use several hand signals that are not used for skin diving. The signals specific to scuba diving relate to air supply.
Scuba divers use several hand signals that are not used for skin diving. The signals specific to scuba diving relate to air supply. Learn and use the standard hand signals shown below. Remember to display hand signals clearly and deliberately and also to acknowledge the hand signals you receive.
Scuba diving hand signals.
Save
Learn more about Scuba Diving, Fifth Edition.
Dive-Planning Factors
Many factors affect your plans for a dive or a diving trip. Keep the following considerations in mind when you are looking ahead to a dive outing.
Many factors affect your plans for a dive or a diving trip. Keep the following considerations in mind when you are looking ahead to a dive outing:
- Health and fitness are important. Illnesses, required medications, and recent operations probably disqualify you for diving. If your health is not normal, consult a diving physician. If there is any doubt about your physical condition, refrain from diving until you are in good health. If you are prone to motion sickness, take steps to try to prevent it.
- Climate is a big factor affecting dive planning. If you dive close to where you live, dive planning is easier than if you intend to dive thousands of miles away. A difference in climate usually means a big difference in diving conditions, which means a difference in your equipment requirements.
- The distance you travel to a diving destination affects your planning. If you travel far to reach the destination, allow a day to rest and recover from travel before you dive. After even one day of repetitive diving, wait one full day before flying home.
- Weather affects diving conditions significantly. Storms and sudden changes in the weather can make diving dangerous. Know the weather forecast, and reschedule your dive if poor weather is predicted. Know the expected wind speed, air temperature, and water conditions.
- Seasonal changes affect water movement, water visibility, air and water temperatures, entry and exit areas, and the presence of certain types of animals. You should know what to expect at a dive site at different times of the year. It helps to know the visibility, water temperatures, tides, surf, surge, currents, bottom composition, silt conditions, plants, and animals.
You need to be physically and mentally fit for diving. Fitness for diving implies that you are well rested, are well nourished, have the physical strength and stamina to meet the requirements of the environment and the activity, are qualified for the activity, are not apprehensive about your plans, are not goaded into doing something you are not prepared to do, and do not allow pride to affect good judgment.
Your objective for the dive affects your planning. Different diving activities require different plans and different equipment. The planning of an underwater photography dive is not the same as the planning of a dive where you intend to hunt for game.
You must know and observe laws, regulations, and customs. Some areas have laws that require the use of a dive flag. Obey fish and game regulations. Some diving professionals discourage the taking of any living thing in an area. You need to know the behavior expected of you. Knowing the expectations in advance can help you avoid being embarrassed at the dive site.
Etiquette is important. Will early-morning diving activities be offensive to residents near the dive site? Will the parking of vehicles at a site irritate people? Be considerate of others who may be in the area where you intend to dive, including those who are fishing nearby. Consider the impact of noise, changing clothes, and dive site access. Then make your plans using good etiquette.
Save
Learn more about Scuba Diving, Fifth Edition.
Selecting a Dive Course
There are many diver training organizations and thousands of professional diving educators. Your phone book might list diving businesses that offer sanctioned courses. Many universities, community colleges, and recreational departments also offer scuba courses.
There are many diver training organizations and thousands of professional diving educators. Your phone book might list diving businesses that offer sanctioned courses. Many universities, community colleges, and recreational departments also offer scuba courses. (See Appendix A for a list of diver training organizations.) Ask about the qualifications, experience, and reputation of several diving instructors in your area to select the course that can provide you with the best possible training. Here are some questions you should ask:
- Is this training sanctioned by a diver training agency?
- How long has the instructor been teaching scuba diving?
- Which levels of training is the instructor qualified to teach?
- May I speak with the graduates of a recent class?
- Why is this course better than others in the area?
- Are assisting and rescue techniques taught in the course?
- How many instructor-supervised open-water dives are included?
The tuition for diving instruction is usually between $200 and $300. The lowest-priced course may not necessarily be a bargain. Find out what is included with the course fee and, more important, what the total cost will be for you to become certified as a scuba diver. You do not have to purchase all the equipment needed to scuba dive, but you need to have a mask, snorkel, fins, and usually boots and gloves for your training (see figure 1.1). Use of the additional required equipment is typically part of the course tuition.
Required scuba diving training equipment.
You should find out whether the price of the course includes the costs of educational materials and certification. There may be additional costs for travel, lodging, parking, boat fees, and equipment rental for open-water training. Determine the complete cost before enrolling in a course.
When you have selected the best program for you and have enrolled in a course, you should receive a reading assignment for your first session. If you are not given an assignment, speak with the instructor; your learning will be enhanced if you read in advance about the topics to be presented in class. Good diving instructors provide a handout with reading assignments.
Learn more about Scuba Diving, Fifth Edition.
Buoyancy
An object’s ability to float in a liquid depends on the density of the object compared with the density of the fluid in which the object is immersed. Water exerts pressure equally in all directions, even upward. You can feel the upward force (buoyancy) of water when you try to push something under the water.
An object's ability to float in a liquid depends on the density of the object compared with the density of the fluid in which the object is immersed. Water exerts pressure equally in all directions, even upward. You can feel the upward force (buoyancy) of water when you try to push something under the water. Buoyancy results from the difference in pressures on the upper and lower surfaces of an object. The weight of an object plus the weight of the fluid (air, water, or both) above the object exert a downward force. Fluid pressure pushes upward from below. The difference between these two forces is the buoyancy of the object.
Archimedes, an ancient Greek scientist, discovered that the force of buoyancy acting on a submerged object equals the weight of the water displaced (this is known as Archimedes' principle). A hot-air balloon floats in air because the hot air inside the balloon weighs less than the volume of cooler air the balloon occupies. A diver is buoyed upward with a force equal to the weight of the water that the diver displaces (see figure 2.8). If you and your equipment weigh less than the weight of the water you displace, you will float, or have positive buoyancy. If you and your equipment weigh more than the water being displaced, you will sink. An object that sinks has negative buoyancy. If you and your equipment weigh exactly the same as the water displaced, you neither float nor sink. Instead, you remain at the depth where you are; you have neutral buoyancy.
Principles of buoyancy.
Learn more about Scuba Diving, Fifth Edition.
Using Scuba Diving Hand Signals
Scuba divers use several hand signals that are not used for skin diving. The signals specific to scuba diving relate to air supply.
Scuba divers use several hand signals that are not used for skin diving. The signals specific to scuba diving relate to air supply. Learn and use the standard hand signals shown below. Remember to display hand signals clearly and deliberately and also to acknowledge the hand signals you receive.
Scuba diving hand signals.
Save
Learn more about Scuba Diving, Fifth Edition.
Dive-Planning Factors
Many factors affect your plans for a dive or a diving trip. Keep the following considerations in mind when you are looking ahead to a dive outing.
Many factors affect your plans for a dive or a diving trip. Keep the following considerations in mind when you are looking ahead to a dive outing:
- Health and fitness are important. Illnesses, required medications, and recent operations probably disqualify you for diving. If your health is not normal, consult a diving physician. If there is any doubt about your physical condition, refrain from diving until you are in good health. If you are prone to motion sickness, take steps to try to prevent it.
- Climate is a big factor affecting dive planning. If you dive close to where you live, dive planning is easier than if you intend to dive thousands of miles away. A difference in climate usually means a big difference in diving conditions, which means a difference in your equipment requirements.
- The distance you travel to a diving destination affects your planning. If you travel far to reach the destination, allow a day to rest and recover from travel before you dive. After even one day of repetitive diving, wait one full day before flying home.
- Weather affects diving conditions significantly. Storms and sudden changes in the weather can make diving dangerous. Know the weather forecast, and reschedule your dive if poor weather is predicted. Know the expected wind speed, air temperature, and water conditions.
- Seasonal changes affect water movement, water visibility, air and water temperatures, entry and exit areas, and the presence of certain types of animals. You should know what to expect at a dive site at different times of the year. It helps to know the visibility, water temperatures, tides, surf, surge, currents, bottom composition, silt conditions, plants, and animals.
You need to be physically and mentally fit for diving. Fitness for diving implies that you are well rested, are well nourished, have the physical strength and stamina to meet the requirements of the environment and the activity, are qualified for the activity, are not apprehensive about your plans, are not goaded into doing something you are not prepared to do, and do not allow pride to affect good judgment.
Your objective for the dive affects your planning. Different diving activities require different plans and different equipment. The planning of an underwater photography dive is not the same as the planning of a dive where you intend to hunt for game.
You must know and observe laws, regulations, and customs. Some areas have laws that require the use of a dive flag. Obey fish and game regulations. Some diving professionals discourage the taking of any living thing in an area. You need to know the behavior expected of you. Knowing the expectations in advance can help you avoid being embarrassed at the dive site.
Etiquette is important. Will early-morning diving activities be offensive to residents near the dive site? Will the parking of vehicles at a site irritate people? Be considerate of others who may be in the area where you intend to dive, including those who are fishing nearby. Consider the impact of noise, changing clothes, and dive site access. Then make your plans using good etiquette.
Save
Learn more about Scuba Diving, Fifth Edition.
Selecting a Dive Course
There are many diver training organizations and thousands of professional diving educators. Your phone book might list diving businesses that offer sanctioned courses. Many universities, community colleges, and recreational departments also offer scuba courses.
There are many diver training organizations and thousands of professional diving educators. Your phone book might list diving businesses that offer sanctioned courses. Many universities, community colleges, and recreational departments also offer scuba courses. (See Appendix A for a list of diver training organizations.) Ask about the qualifications, experience, and reputation of several diving instructors in your area to select the course that can provide you with the best possible training. Here are some questions you should ask:
- Is this training sanctioned by a diver training agency?
- How long has the instructor been teaching scuba diving?
- Which levels of training is the instructor qualified to teach?
- May I speak with the graduates of a recent class?
- Why is this course better than others in the area?
- Are assisting and rescue techniques taught in the course?
- How many instructor-supervised open-water dives are included?
The tuition for diving instruction is usually between $200 and $300. The lowest-priced course may not necessarily be a bargain. Find out what is included with the course fee and, more important, what the total cost will be for you to become certified as a scuba diver. You do not have to purchase all the equipment needed to scuba dive, but you need to have a mask, snorkel, fins, and usually boots and gloves for your training (see figure 1.1). Use of the additional required equipment is typically part of the course tuition.
Required scuba diving training equipment.
You should find out whether the price of the course includes the costs of educational materials and certification. There may be additional costs for travel, lodging, parking, boat fees, and equipment rental for open-water training. Determine the complete cost before enrolling in a course.
When you have selected the best program for you and have enrolled in a course, you should receive a reading assignment for your first session. If you are not given an assignment, speak with the instructor; your learning will be enhanced if you read in advance about the topics to be presented in class. Good diving instructors provide a handout with reading assignments.
Learn more about Scuba Diving, Fifth Edition.
Buoyancy
An object’s ability to float in a liquid depends on the density of the object compared with the density of the fluid in which the object is immersed. Water exerts pressure equally in all directions, even upward. You can feel the upward force (buoyancy) of water when you try to push something under the water.
An object's ability to float in a liquid depends on the density of the object compared with the density of the fluid in which the object is immersed. Water exerts pressure equally in all directions, even upward. You can feel the upward force (buoyancy) of water when you try to push something under the water. Buoyancy results from the difference in pressures on the upper and lower surfaces of an object. The weight of an object plus the weight of the fluid (air, water, or both) above the object exert a downward force. Fluid pressure pushes upward from below. The difference between these two forces is the buoyancy of the object.
Archimedes, an ancient Greek scientist, discovered that the force of buoyancy acting on a submerged object equals the weight of the water displaced (this is known as Archimedes' principle). A hot-air balloon floats in air because the hot air inside the balloon weighs less than the volume of cooler air the balloon occupies. A diver is buoyed upward with a force equal to the weight of the water that the diver displaces (see figure 2.8). If you and your equipment weigh less than the weight of the water you displace, you will float, or have positive buoyancy. If you and your equipment weigh more than the water being displaced, you will sink. An object that sinks has negative buoyancy. If you and your equipment weigh exactly the same as the water displaced, you neither float nor sink. Instead, you remain at the depth where you are; you have neutral buoyancy.
Principles of buoyancy.
Learn more about Scuba Diving, Fifth Edition.
Using Scuba Diving Hand Signals
Scuba divers use several hand signals that are not used for skin diving. The signals specific to scuba diving relate to air supply.
Scuba divers use several hand signals that are not used for skin diving. The signals specific to scuba diving relate to air supply. Learn and use the standard hand signals shown below. Remember to display hand signals clearly and deliberately and also to acknowledge the hand signals you receive.
Scuba diving hand signals.
Save
Learn more about Scuba Diving, Fifth Edition.
Dive-Planning Factors
Many factors affect your plans for a dive or a diving trip. Keep the following considerations in mind when you are looking ahead to a dive outing.
Many factors affect your plans for a dive or a diving trip. Keep the following considerations in mind when you are looking ahead to a dive outing:
- Health and fitness are important. Illnesses, required medications, and recent operations probably disqualify you for diving. If your health is not normal, consult a diving physician. If there is any doubt about your physical condition, refrain from diving until you are in good health. If you are prone to motion sickness, take steps to try to prevent it.
- Climate is a big factor affecting dive planning. If you dive close to where you live, dive planning is easier than if you intend to dive thousands of miles away. A difference in climate usually means a big difference in diving conditions, which means a difference in your equipment requirements.
- The distance you travel to a diving destination affects your planning. If you travel far to reach the destination, allow a day to rest and recover from travel before you dive. After even one day of repetitive diving, wait one full day before flying home.
- Weather affects diving conditions significantly. Storms and sudden changes in the weather can make diving dangerous. Know the weather forecast, and reschedule your dive if poor weather is predicted. Know the expected wind speed, air temperature, and water conditions.
- Seasonal changes affect water movement, water visibility, air and water temperatures, entry and exit areas, and the presence of certain types of animals. You should know what to expect at a dive site at different times of the year. It helps to know the visibility, water temperatures, tides, surf, surge, currents, bottom composition, silt conditions, plants, and animals.
You need to be physically and mentally fit for diving. Fitness for diving implies that you are well rested, are well nourished, have the physical strength and stamina to meet the requirements of the environment and the activity, are qualified for the activity, are not apprehensive about your plans, are not goaded into doing something you are not prepared to do, and do not allow pride to affect good judgment.
Your objective for the dive affects your planning. Different diving activities require different plans and different equipment. The planning of an underwater photography dive is not the same as the planning of a dive where you intend to hunt for game.
You must know and observe laws, regulations, and customs. Some areas have laws that require the use of a dive flag. Obey fish and game regulations. Some diving professionals discourage the taking of any living thing in an area. You need to know the behavior expected of you. Knowing the expectations in advance can help you avoid being embarrassed at the dive site.
Etiquette is important. Will early-morning diving activities be offensive to residents near the dive site? Will the parking of vehicles at a site irritate people? Be considerate of others who may be in the area where you intend to dive, including those who are fishing nearby. Consider the impact of noise, changing clothes, and dive site access. Then make your plans using good etiquette.
Save
Learn more about Scuba Diving, Fifth Edition.
Selecting a Dive Course
There are many diver training organizations and thousands of professional diving educators. Your phone book might list diving businesses that offer sanctioned courses. Many universities, community colleges, and recreational departments also offer scuba courses.
There are many diver training organizations and thousands of professional diving educators. Your phone book might list diving businesses that offer sanctioned courses. Many universities, community colleges, and recreational departments also offer scuba courses. (See Appendix A for a list of diver training organizations.) Ask about the qualifications, experience, and reputation of several diving instructors in your area to select the course that can provide you with the best possible training. Here are some questions you should ask:
- Is this training sanctioned by a diver training agency?
- How long has the instructor been teaching scuba diving?
- Which levels of training is the instructor qualified to teach?
- May I speak with the graduates of a recent class?
- Why is this course better than others in the area?
- Are assisting and rescue techniques taught in the course?
- How many instructor-supervised open-water dives are included?
The tuition for diving instruction is usually between $200 and $300. The lowest-priced course may not necessarily be a bargain. Find out what is included with the course fee and, more important, what the total cost will be for you to become certified as a scuba diver. You do not have to purchase all the equipment needed to scuba dive, but you need to have a mask, snorkel, fins, and usually boots and gloves for your training (see figure 1.1). Use of the additional required equipment is typically part of the course tuition.
Required scuba diving training equipment.
You should find out whether the price of the course includes the costs of educational materials and certification. There may be additional costs for travel, lodging, parking, boat fees, and equipment rental for open-water training. Determine the complete cost before enrolling in a course.
When you have selected the best program for you and have enrolled in a course, you should receive a reading assignment for your first session. If you are not given an assignment, speak with the instructor; your learning will be enhanced if you read in advance about the topics to be presented in class. Good diving instructors provide a handout with reading assignments.
Learn more about Scuba Diving, Fifth Edition.
Buoyancy
An object’s ability to float in a liquid depends on the density of the object compared with the density of the fluid in which the object is immersed. Water exerts pressure equally in all directions, even upward. You can feel the upward force (buoyancy) of water when you try to push something under the water.
An object's ability to float in a liquid depends on the density of the object compared with the density of the fluid in which the object is immersed. Water exerts pressure equally in all directions, even upward. You can feel the upward force (buoyancy) of water when you try to push something under the water. Buoyancy results from the difference in pressures on the upper and lower surfaces of an object. The weight of an object plus the weight of the fluid (air, water, or both) above the object exert a downward force. Fluid pressure pushes upward from below. The difference between these two forces is the buoyancy of the object.
Archimedes, an ancient Greek scientist, discovered that the force of buoyancy acting on a submerged object equals the weight of the water displaced (this is known as Archimedes' principle). A hot-air balloon floats in air because the hot air inside the balloon weighs less than the volume of cooler air the balloon occupies. A diver is buoyed upward with a force equal to the weight of the water that the diver displaces (see figure 2.8). If you and your equipment weigh less than the weight of the water you displace, you will float, or have positive buoyancy. If you and your equipment weigh more than the water being displaced, you will sink. An object that sinks has negative buoyancy. If you and your equipment weigh exactly the same as the water displaced, you neither float nor sink. Instead, you remain at the depth where you are; you have neutral buoyancy.
Principles of buoyancy.
Learn more about Scuba Diving, Fifth Edition.
Using Scuba Diving Hand Signals
Scuba divers use several hand signals that are not used for skin diving. The signals specific to scuba diving relate to air supply.
Scuba divers use several hand signals that are not used for skin diving. The signals specific to scuba diving relate to air supply. Learn and use the standard hand signals shown below. Remember to display hand signals clearly and deliberately and also to acknowledge the hand signals you receive.
Scuba diving hand signals.
Save
Learn more about Scuba Diving, Fifth Edition.
Dive-Planning Factors
Many factors affect your plans for a dive or a diving trip. Keep the following considerations in mind when you are looking ahead to a dive outing.
Many factors affect your plans for a dive or a diving trip. Keep the following considerations in mind when you are looking ahead to a dive outing:
- Health and fitness are important. Illnesses, required medications, and recent operations probably disqualify you for diving. If your health is not normal, consult a diving physician. If there is any doubt about your physical condition, refrain from diving until you are in good health. If you are prone to motion sickness, take steps to try to prevent it.
- Climate is a big factor affecting dive planning. If you dive close to where you live, dive planning is easier than if you intend to dive thousands of miles away. A difference in climate usually means a big difference in diving conditions, which means a difference in your equipment requirements.
- The distance you travel to a diving destination affects your planning. If you travel far to reach the destination, allow a day to rest and recover from travel before you dive. After even one day of repetitive diving, wait one full day before flying home.
- Weather affects diving conditions significantly. Storms and sudden changes in the weather can make diving dangerous. Know the weather forecast, and reschedule your dive if poor weather is predicted. Know the expected wind speed, air temperature, and water conditions.
- Seasonal changes affect water movement, water visibility, air and water temperatures, entry and exit areas, and the presence of certain types of animals. You should know what to expect at a dive site at different times of the year. It helps to know the visibility, water temperatures, tides, surf, surge, currents, bottom composition, silt conditions, plants, and animals.
You need to be physically and mentally fit for diving. Fitness for diving implies that you are well rested, are well nourished, have the physical strength and stamina to meet the requirements of the environment and the activity, are qualified for the activity, are not apprehensive about your plans, are not goaded into doing something you are not prepared to do, and do not allow pride to affect good judgment.
Your objective for the dive affects your planning. Different diving activities require different plans and different equipment. The planning of an underwater photography dive is not the same as the planning of a dive where you intend to hunt for game.
You must know and observe laws, regulations, and customs. Some areas have laws that require the use of a dive flag. Obey fish and game regulations. Some diving professionals discourage the taking of any living thing in an area. You need to know the behavior expected of you. Knowing the expectations in advance can help you avoid being embarrassed at the dive site.
Etiquette is important. Will early-morning diving activities be offensive to residents near the dive site? Will the parking of vehicles at a site irritate people? Be considerate of others who may be in the area where you intend to dive, including those who are fishing nearby. Consider the impact of noise, changing clothes, and dive site access. Then make your plans using good etiquette.
Save
Learn more about Scuba Diving, Fifth Edition.
Selecting a Dive Course
There are many diver training organizations and thousands of professional diving educators. Your phone book might list diving businesses that offer sanctioned courses. Many universities, community colleges, and recreational departments also offer scuba courses.
There are many diver training organizations and thousands of professional diving educators. Your phone book might list diving businesses that offer sanctioned courses. Many universities, community colleges, and recreational departments also offer scuba courses. (See Appendix A for a list of diver training organizations.) Ask about the qualifications, experience, and reputation of several diving instructors in your area to select the course that can provide you with the best possible training. Here are some questions you should ask:
- Is this training sanctioned by a diver training agency?
- How long has the instructor been teaching scuba diving?
- Which levels of training is the instructor qualified to teach?
- May I speak with the graduates of a recent class?
- Why is this course better than others in the area?
- Are assisting and rescue techniques taught in the course?
- How many instructor-supervised open-water dives are included?
The tuition for diving instruction is usually between $200 and $300. The lowest-priced course may not necessarily be a bargain. Find out what is included with the course fee and, more important, what the total cost will be for you to become certified as a scuba diver. You do not have to purchase all the equipment needed to scuba dive, but you need to have a mask, snorkel, fins, and usually boots and gloves for your training (see figure 1.1). Use of the additional required equipment is typically part of the course tuition.
Required scuba diving training equipment.
You should find out whether the price of the course includes the costs of educational materials and certification. There may be additional costs for travel, lodging, parking, boat fees, and equipment rental for open-water training. Determine the complete cost before enrolling in a course.
When you have selected the best program for you and have enrolled in a course, you should receive a reading assignment for your first session. If you are not given an assignment, speak with the instructor; your learning will be enhanced if you read in advance about the topics to be presented in class. Good diving instructors provide a handout with reading assignments.
Learn more about Scuba Diving, Fifth Edition.
Buoyancy
An object’s ability to float in a liquid depends on the density of the object compared with the density of the fluid in which the object is immersed. Water exerts pressure equally in all directions, even upward. You can feel the upward force (buoyancy) of water when you try to push something under the water.
An object's ability to float in a liquid depends on the density of the object compared with the density of the fluid in which the object is immersed. Water exerts pressure equally in all directions, even upward. You can feel the upward force (buoyancy) of water when you try to push something under the water. Buoyancy results from the difference in pressures on the upper and lower surfaces of an object. The weight of an object plus the weight of the fluid (air, water, or both) above the object exert a downward force. Fluid pressure pushes upward from below. The difference between these two forces is the buoyancy of the object.
Archimedes, an ancient Greek scientist, discovered that the force of buoyancy acting on a submerged object equals the weight of the water displaced (this is known as Archimedes' principle). A hot-air balloon floats in air because the hot air inside the balloon weighs less than the volume of cooler air the balloon occupies. A diver is buoyed upward with a force equal to the weight of the water that the diver displaces (see figure 2.8). If you and your equipment weigh less than the weight of the water you displace, you will float, or have positive buoyancy. If you and your equipment weigh more than the water being displaced, you will sink. An object that sinks has negative buoyancy. If you and your equipment weigh exactly the same as the water displaced, you neither float nor sink. Instead, you remain at the depth where you are; you have neutral buoyancy.
Principles of buoyancy.
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Using Scuba Diving Hand Signals
Scuba divers use several hand signals that are not used for skin diving. The signals specific to scuba diving relate to air supply.
Scuba divers use several hand signals that are not used for skin diving. The signals specific to scuba diving relate to air supply. Learn and use the standard hand signals shown below. Remember to display hand signals clearly and deliberately and also to acknowledge the hand signals you receive.
Scuba diving hand signals.
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Dive-Planning Factors
Many factors affect your plans for a dive or a diving trip. Keep the following considerations in mind when you are looking ahead to a dive outing.
Many factors affect your plans for a dive or a diving trip. Keep the following considerations in mind when you are looking ahead to a dive outing:
- Health and fitness are important. Illnesses, required medications, and recent operations probably disqualify you for diving. If your health is not normal, consult a diving physician. If there is any doubt about your physical condition, refrain from diving until you are in good health. If you are prone to motion sickness, take steps to try to prevent it.
- Climate is a big factor affecting dive planning. If you dive close to where you live, dive planning is easier than if you intend to dive thousands of miles away. A difference in climate usually means a big difference in diving conditions, which means a difference in your equipment requirements.
- The distance you travel to a diving destination affects your planning. If you travel far to reach the destination, allow a day to rest and recover from travel before you dive. After even one day of repetitive diving, wait one full day before flying home.
- Weather affects diving conditions significantly. Storms and sudden changes in the weather can make diving dangerous. Know the weather forecast, and reschedule your dive if poor weather is predicted. Know the expected wind speed, air temperature, and water conditions.
- Seasonal changes affect water movement, water visibility, air and water temperatures, entry and exit areas, and the presence of certain types of animals. You should know what to expect at a dive site at different times of the year. It helps to know the visibility, water temperatures, tides, surf, surge, currents, bottom composition, silt conditions, plants, and animals.
You need to be physically and mentally fit for diving. Fitness for diving implies that you are well rested, are well nourished, have the physical strength and stamina to meet the requirements of the environment and the activity, are qualified for the activity, are not apprehensive about your plans, are not goaded into doing something you are not prepared to do, and do not allow pride to affect good judgment.
Your objective for the dive affects your planning. Different diving activities require different plans and different equipment. The planning of an underwater photography dive is not the same as the planning of a dive where you intend to hunt for game.
You must know and observe laws, regulations, and customs. Some areas have laws that require the use of a dive flag. Obey fish and game regulations. Some diving professionals discourage the taking of any living thing in an area. You need to know the behavior expected of you. Knowing the expectations in advance can help you avoid being embarrassed at the dive site.
Etiquette is important. Will early-morning diving activities be offensive to residents near the dive site? Will the parking of vehicles at a site irritate people? Be considerate of others who may be in the area where you intend to dive, including those who are fishing nearby. Consider the impact of noise, changing clothes, and dive site access. Then make your plans using good etiquette.
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Selecting a Dive Course
There are many diver training organizations and thousands of professional diving educators. Your phone book might list diving businesses that offer sanctioned courses. Many universities, community colleges, and recreational departments also offer scuba courses.
There are many diver training organizations and thousands of professional diving educators. Your phone book might list diving businesses that offer sanctioned courses. Many universities, community colleges, and recreational departments also offer scuba courses. (See Appendix A for a list of diver training organizations.) Ask about the qualifications, experience, and reputation of several diving instructors in your area to select the course that can provide you with the best possible training. Here are some questions you should ask:
- Is this training sanctioned by a diver training agency?
- How long has the instructor been teaching scuba diving?
- Which levels of training is the instructor qualified to teach?
- May I speak with the graduates of a recent class?
- Why is this course better than others in the area?
- Are assisting and rescue techniques taught in the course?
- How many instructor-supervised open-water dives are included?
The tuition for diving instruction is usually between $200 and $300. The lowest-priced course may not necessarily be a bargain. Find out what is included with the course fee and, more important, what the total cost will be for you to become certified as a scuba diver. You do not have to purchase all the equipment needed to scuba dive, but you need to have a mask, snorkel, fins, and usually boots and gloves for your training (see figure 1.1). Use of the additional required equipment is typically part of the course tuition.
Required scuba diving training equipment.
You should find out whether the price of the course includes the costs of educational materials and certification. There may be additional costs for travel, lodging, parking, boat fees, and equipment rental for open-water training. Determine the complete cost before enrolling in a course.
When you have selected the best program for you and have enrolled in a course, you should receive a reading assignment for your first session. If you are not given an assignment, speak with the instructor; your learning will be enhanced if you read in advance about the topics to be presented in class. Good diving instructors provide a handout with reading assignments.
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