Reaper leviathans keep wrecking my seamoth

they make a loud roar before they come in, so the moment you hear one, turn and head the other way and kill your engine noise by stopping for a sec if it's close. the perimeter defense upgrade will make one let go if it grabs you. honestly though the real fix is not taking the seamoth through their areas at all, the crash zone and dunes are reaper country, and the prawn suit handles them much better.