DESTROYERS
...stay well away. run when you can - and you'll (probably) need more than 200 yards for the torp to charge itself before detonation is possible.
i have tried the run-in attack on destroyers and have scored against them with the torpedo trick - but, it only works for so long. while you are playing cat and mouse with one (and wasting battery life too) its friends are on their way: now you are lucky or dead
take care