The chief danger in the Antarctic is the cold. Hypothermia can kill a man in minutes should they even get wet, much less fall into the frigid water.
And yet of the Vendetta's crew of 21, only one died of hypothermia. The other twenty found nice warm accommodations. Even the one who fell in the water and drowned was subsequently warmed back up. You could call that extraordinarily good luck were it not for the nature of the places they ended up.
From the perspective of a person being digested there is little practical difference between the stomachs of a massive leopard seal, a normal sized one and a dolphin. It might be a bit tighter in there but the end result is the same. 83