Scuba divers control their buoyancy to keep off the sea floor or from floating up to the surface, to avoid obstacles both above and below them, and to have a more relaxing dive with minimal physical effort. As a diver changes depth, they need to either add or release air from their buoyancy compensator (BC or BCD) to maintain neutral buoyancy. A diver in control of their buoyancy can move through the water with minimal fin input and breath control making the dive a lot more enjoyable (not to mention longer due to not using a lot of air inefficiently to maintain buoyancy control).
Buoyancy is not really used by scuba divers, but it does act against them. Since the human body and the gear during scuba diving is held up by the water, especially at farther down depths of the ocean, where the water is more dense because of the weight of the water and the air holding it down. Because of the buoyancy, the divers have to wear weights to offset this buoyancy. Since in scuba diving you use wetsuits, and since these suits have nitrogen bubbles to assist insulation, this makes you float even more. And since your cells contain lipids and other materiels that are lighter than the water, this makes you float even more. This means that scuba divers must use weights to offset the buoyancy.
swallow water
The primary buoyancy control is by the mass of the equipment and weight-belt versus the diver's natural buoyancy and that of the suit; but divers also use an adjustable buoyancy jacket for fine control.
The collective noun is a bubble of scuba divers.
A buoyancy compensator, typically worn by scuba divers, is a piece of equipment that helps control the diver's buoyancy underwater. It can be inflated or deflated to adjust buoyancy and maintain a desired depth. It also provides a means for attaching other diving equipment and can serve as a flotation device on the surface.
Many people use a SCUBA suit for diving. Sport divers, police divers and some Navy recovery divers.
scuba divers
Equipment changes depending on the location of the dive and purpose. Basic equipment include, wetsuit, fins, snorkel and mask, lead weight, scuba tank, BCD (Buoyancy Compensation Device), and Regulator.
Free divers do but scuba divers do not need to. Scuba divers take their air with them and would have no need to hyperventilate.
They swim
seebees
Buoyancy is not required in order for a SCUBA diver to explore the underwater world. It is required only when his session is complete, and he wishes to rise to the surface, replenish his survival resources, and live to explore on another day.
Divers adjust their buoyancy using their BCD (buoyancy control device) by adding or releasing air to maintain neutral buoyancy. By controlling their buoyancy, divers can achieve a state where they neither sink nor float, allowing them to hover at a desired depth.