Perhaps shows and movies portraying the US armed forces are a bit exxagerated here and there, but I would guess that any navy or coast guard boat/ship would have some sort of portable defibrillator or just basic emergency medical equipment. Seems none of them had any medical training past the basics and no knowledge of basic symptoms that would be logical to know for their locale. Either Australia's Navy has no budget for basic supplies and training, or this show is about a ship full of the worst seamen in Australia.