Weight System

Lead weights carried on a belt or in BCD pockets that offset the buoyancy of the diver, suit, and gear so descent is possible.

The weight system is the lead that lets you leave the surface. A diver in a wetsuit with an aluminum tank is naturally buoyant, so without added weight you simply cannot descend. Weights are carried on a webbing belt, in quick-release integrated pockets on the BCD, or distributed into trim pockets near the tank to fine tune body position in the water.

The amount matters enormously. Overweighted divers carry extra air in the BCD to compensate, which expands and contracts with depth and makes buoyancy control twitchy, while underweighted divers struggle to hold the 5 m safety stop with a near-empty tank. A proper weight check aims for floating at eye level with an empty BCD and a normal breath, then accounts for the roughly 2 kg an aluminum 80 gains in buoyancy as it empties.

Every system must have a quick release you can operate with one hand, because ditching weights is the last resort for establishing positive buoyancy at the surface. Note your weighting, suit, and tank type in your logbook so you never have to guess again at a new destination.