This former Blogger draft was fully rewritten, fact-checked and updated in July 2026.
Correct weighting is not about finding a number that works forever. It is about finding the minimum ballast needed for a specific diver, cylinder, exposure suit, water type and equipment configuration.
Overweighting is common because descending feels easier at the beginning. The cost appears later: more gas in the BCD, greater drag, unstable buoyancy and a more difficult ascent.
Use the complete configuration
A meaningful weight check is done with the equipment you will actually dive: cylinder, regulator, BCD or wing, exposure suit, accessories and the gas quantity planned for the check. Removing the cylinder makes the result irrelevant because cylinders have their own buoyancy characteristics.
The surface check
- Enter water deep enough to float vertically without standing or kicking.
- Empty the BCD completely and confirm that hidden air is not trapped.
- Hold a normal breath, remain still and observe the water level around the eyes.
- Exhale normally. A correctly weighted diver should begin a slow, controlled descent rather than dropping rapidly.
Confirm it near the end of a dive
The best confirmation is performed with a nearly empty cylinder—commonly around 35–50 bar, or 500–750 psi—because the cylinder is more buoyant after gas has been consumed. At the safety-stop depth, with the BCD empty, you should be able to hold position comfortably without pulling yourself down.
Weight and trim are different problems
Once total ballast is correct, move small amounts between belt, trim pockets or backplate positions to obtain stable horizontal trim. Adding more lead to solve poor trim usually creates a new buoyancy problem.
Record the result
Log the cylinder material and size, water type, suit thickness, undergarment, total lead and where it was placed. My logbook is one reason I can change configuration without starting from zero every time.
