A Buoyancy Compensator must provide a minimum positive buoyancy at maximum depth of how many pounds?

• A. 5 pounds
• B. 10 pounds
• C. 15 pounds
• D. 20 pounds

Answer: (B)

When you dive, buoyancy is not constant. The air in your buoyancy compensator compresses as you descend, so the jacket’s lift at depth is less than its lift at the surface. That means there must be some safety margin of positive buoyancy remaining even when the BCD is fully compressed at the deepest part of the dive. A practical and widely used standard sets this minimum margin at ten pounds of positive buoyancy. This amount is enough to help you initiate an ascent or maintain upward movement if other factors—like weights or a dry suit adding negative buoyancy—come into play, without making buoyancy control cumbersome in normal situations. Ten pounds strikes a balance: it’s enough safety margin, but not so large that it becomes unnecessarily difficult to trim neutral at depth or swerve into over-buoyancy during routine dives.