I noticed that with magnetic trigger one can have a greater angle . you can sink anyship with one torpedoe you have to hit the boiler the site differs according to ships .that what happened in real with the "sadly known" (or not depends on which side one places itself) Lusitania which made 30000t the commandant of the U-boat had only one torpedoe left he hits the boiler room as the ship was at the end of its way rhe coal room was empty and the coal dust reacted to the explosion as black powder would have done it the ship has litteraly been desintegreted later others said that in fact such an explosion couldn t have been made only by a weapons load
Lusitania Wikipedia