Does a divers bouyancy change with depth?

Answer 1

Absolutely - air compresses at depth, and because wetsuits are made up of air cells, they compress and lose buoyancy along with the air in the BCD, so divers have to add air while descending. Also, as you breathe air, the tank gets about 6 pounds lighter during the dive, so you need to release air. Finally, as air expands while ascending, you need to let air out.