One more fucking time, as this is clearly hard for some of you to understand. When a whale dies of entanglement it is because it is usually because drowns, as I am sure you know they do have to surface to breathe. As they accumulate more and more fixed lines the weight of it makes it impossible to surface as they grow more and more exhausted. When they finally give up the ghost, the weight of all that tac keeps them under. If that whale, with all it's strength and endurance can no manage to surface then the natural tendency for them to "float" on death is sure as fuck not going to be able to. The other way entanglements can kill them is if the wounds caused by the lines become infected.