Abstract: An air supply and exhaust system used for a buoyancy compensator includes an air supply and exhaust unit attached to a jacket, a manipulating unit connected to a hose extending from an air cylinder and first and second hoses connected to these two units. The air supply and exhaust unit uses the air supplied from the manipulating unit to supply the air to the jacket and to open an air exhaust valve and thereby to exhaust the air from the jacket. The manipulating unit uses a rotary change-over switch to supply the air from an air cylinder to a main supply pipe or an air chamber of the air supply and exhaust unit.

Abstract: An air supply and exhaust system used for a buoyancy compensator includes an air supply and exhaust unit attached to a jacket, a manipulating unit connected to a hose extending from an air cylinder and first and second hoses connected to these two units. The air supply and exhaust unit uses the air supplied from the manipulating unit to supply the air to the jacket and to open an air exhaust valve and thereby to exhaust the air from the jacket. The manipulating unit uses a rotary change-over switch to supply the air from an air cylinder to a main supply pipe or an air chamber of the air supply and exhaust unit.

Abstract: A buoyancy compensating jacket is provided on a waist portion with a pocket having a first flap, a pouch having a flat cord adapted to be inserted into and taken out from the pocket with a weight packed into the pouch. As a guide means for the flat cord, at least one of a substantially C-shaped guide ring provided at a distal end of the first flap substantially in the vertically middle and a groove formed on an outer surface of the pocket and/or an inner surface of the first flap substantially in the vertically middle.