# Is there a depth under which the buoyant force is no longer sufficient to bring a diver back to the surface? [duplicate]

I came across the story of diver Yuri Lipski who died while diving in the Blue Hole.

This made me wonder something and it may be a stupid question but I thought I'd ask:

For a human diver with normal gear i.e. just a bottle of oxygen, is there a depth under which the pressure of the water above exceeds the buoyancy force the diver is subject to, causing him/her to sink to the bottom?

• If the lungs collapse you are no longer buoyant. Commented Jun 9, 2023 at 12:32
• Does this answer your question? Is there a depth at which a human body, with lungs full of air, will no longer float?
– Amit
Commented Jun 9, 2023 at 12:49
• FYI: "normal gear" for a recreational diver includes a Buoyancy Compenstor (a.k.a., "BC"). It's an inflatable vest, with valves that the diver can use to let air in from their breathing supply, or let air out as needed to maintain neutral buoyancy. FYI2: The buoyancy of a wet suit decreases with depth because increasing ambient pressure compresses the gas trapped in the closed-cell foam and changes its density. A diver wearing a heavy wet suit has to fiddle with their BC more often than a "skin diver" has to do. Commented Jun 9, 2023 at 15:10
• FYI3: A rec diver's air bottles become increasingly buoyant throughout the dive. A standard "80 cubic foot" dive bottle holds almost three kilograms of air when it's full, so weighs almost three kilos less at the end of a long dive as it did to begin with. That's the other main reason why the diver must adjust their BC during the dive. Commented Jun 9, 2023 at 15:16