I don't know for sure, but divers do carry their own breathing source, and therefore have more freedom to dive.
I think that depends on the source of breathing. Gas or compressed air which allows them them greater independence and freedom of movement
Scuba Diving is an interesting thing.  There's a lot of ocean science involved. Yes, scuba diving involves being completely untethered from the surface air supply. Have you ever been scuba diving? No, I haven't. How far down can scuba divers go?
Scuba divers carry their own source of breathing gas, usually compressed air, allowing them greater independence and freedom of movement than surface-supplied divers, and longer underwater endurance than breath-hold divers.