Diving weighting system

Divers wear weighting systems, weight belts or weights to counteract the buoyancy of other diving equipment, such as diving suits and aluminium diving cylinders. The scuba diver must be weighted sufficiently to be negatively buoyant at the end of the dive when most of the breathing gas has been used, and needs to maintain neutral buoyancy at safety or obligatory decompression stops. During the dive, buoyancy is controlled by adjusting the volume of air in the Buoyancy Compensation Device (BCD) and, if worn, the dry suit, in order to achieve neutral or positive buoyancy as needed. The amount of weight required is determined by the maximum overall positive buoyancy of the fully equipped but unweighted diver anticipated during the dive, with an empty buoyancy compensator and normally inflated dry suit. This depends on the diver's mass and body composition, buoyancy of other diving gear worn (especially the diving suit), water salinity, and water temperature. It normally is in the range of 2 kilograms (4.4 lb) to 15 kilograms (33 lb).