Weight Check

A surface test of correct weighting: with an empty BCD and a normal breath held, a properly weighted diver floats at eye level and sinks slowly on exhaling.

A weight check is the quick surface test that tells you whether you are carrying the right amount of lead. The standard version: in water too deep to stand, fully geared, empty your BCD completely, hold a normal breath, and hang motionless. Correctly weighted, you float at roughly eye level; when you exhale, you sink slowly. Bob at the shoulders and you are underweighted, drop like a stone and you are overweighted. Because a tank loses about 2 kg (5 lb) of gas weight as you breathe it down, the classic refinement is to add that margin, or better, repeat the check with a near-empty tank at the end of the dive.

Correct weighting is the foundation every buoyancy skill stands on. An overweighted diver must carry a big compensating bubble in the BCD, and that bubble expands and contracts with every depth change, making neutral buoyancy a constant fight, wrecking trim, and inflating gas consumption. An underweighted diver cannot stay down for the safety stop with a light tank, exactly when floating up is most dangerous. Most new divers are overweighted, and shedding lead gradually as comfort grows is a normal part of progression.

Your weighting changes with every variable: salt versus fresh water, wetsuit thickness or a drysuit, tank material and size, even body composition over time. Recheck whenever the configuration changes, and record the exact lead, suit, and tank in your dive log, that one habit turns every future weight check into a 10 second confirmation instead of a fresh experiment at the start of every trip.