IF you are askin in RL ? well the answer is any.Howeever that is if there is no crew to stop the floodings.IN time (if you make holes in enoughcompartments) the ship will sink(though this may take days
). IN the game i use torps (especialy 41 and after) and if the ship is small enoguh and doesnt deserve a second fish i use the Deck gun to finish it.
I would advise you to try sink ships after 41 with deck gun only (unless very small).I would recomend you either get in gun duels with armed merchants also and always make sure before using the deck gun that your target is unarmed or their guns cant targe tyou.Ive done all this mystakes and they cost crewmembers and careers
