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 compensator (diving) to think much about it. Skilled scuba divers may often be identified by the their ability to maintain constant depth without fin use, as fish do. The vertical-horizontal orientation, or trim, of the submerged diver is influenced by the BC and by other buoyancy and weight components and contributed to by the diver's body, clothing and equipment. The diver typically wishes to be positioned nearly horizontally (prone) while under water, to be able to see and swim usefully, but more nearly vertical and perhaps partly supine, to be able to breathe without a regulator when on the surface. Buoyancy and