Aha. So this is only with scuba divers, not free divers...that the buoyancy thing becomes an issue?
“Aha. So this is only with scuba divers, not free divers...that the buoyancy thing becomes an issue?”
Not really, your lungs are a major component of your buoyancy. At normal depths you can you your breathing to help manage your depth.
At 300 feet your lungs are providing much less buoyancy than at 15 feet. If she blacked out she would not float up. If she can’t kick she also won’t be able to ascend.