Neutral buoyancy diver maintains neutral buoyancy by continuous correction, usually by controlled breathing, as neutral buoyancy is an unstable condition for a compressible object in a liquid. The mathematician Archimedes discovered much of how buoyancy works more than 2000 years ago. In his research, Archimedes discovered that an object is buoyed up by a force equal to the weight of the water displaced by the object. In other words, an inflatable boat that displaces 100 pounds (45 kilograms) of water is buoyed up by that same weight of support. An object that floats in the water is known as being "positively" buoyant.
Buoyancy aid Buoyancy aid Buoyancy aids are a specialist form of "personal flotation device" (PFD) used most commonly by kayakers, canoeists and dinghy sailors. They are designed as a flotation aid, rather than a life-saving device and have several key differences to other PFD's and lifejackets. Regardless of the specification of buoyancy aids, they do not provide (nor are they intended to) the same high level of protection as lifejackets. Therefore, they should not be used as a substitute for a life-jacket, particularly where children are concerned. Canoeing and kayaking buoyancy aids are designed with mobility in mind. A buoyancy aid that