Factors that affect a diver’s buoyancy.
Below are some of the items that will have an affect on your buoyancy while you are diving.
- Your Breathing and the air in the Lungs. The air volume in a diver’s lungs will influence buoyancy. As a diver breathes out, the lungs and chest become slightly smaller. This decreases the displaced water making them more negatively buoyant. Upon inhalation the lungs inflate and increases the amount of water he displaces, making him slightly positively buoyant. For this reason, divers are taught to exhale on the surface to begin their descent this helping them to sink. Then during the dive, the diver is to breathe normally thus reducing any signification fluctuations in lung volume.
- Your Body Type: We all are who we are so the key here is to be honest with yourself. Muscle is denser and sinks, fats are less dense and float. The higher a diver’s ratio of fat to muscle, the more buoyant they will be. Women generally have a higher percentage of body fat than men and are therefore more buoyant and need more weight. This is the reason that body builders sink in a pool, while the average person can float.
- Exposure Protection: All suits are not the same and getting the right suit for your body type and diving conditions are important to match. The thicker (or longer) a suit the more buoyant it will be. So, minimum is great so long as you have the correct protection, usually thermal, for the dive you on are.
- Tank Pressure: Air has weight. Because you start with a full tank and then use the air in the tank you will therefore have less weight towards the end of the dive. The volume of the tank and the weight of the tank remains the same during a dive, but the amount of air inside the tank does not. At the beginning of a dive standard aluminum 80 cubic foot tank is about 2 pounds negatively buoyant, while at the end of the dive it is about 4 pounds positively buoyant.
- Dive Gear: The gear you choose and bring with you on the dive all affects buoyancy. Select each piece of gear with overall buoyancy in mind as many options can be found that positive, neutral or negative.