hey everybody,
i had the same prob yesterday, i wanted to torp a merchant( ~8000 t) with a 2 torp salvo. both of them did not explode.
the day before i torped a merchant( ~4000t) with magnetic pistol and it exploded right under the keel...
in both cases i set the deth 0,8 m under keel deth.
it is very confusing to me.
6 months ago i had read something about to change some values in each sim file(not really sure about that type of file) and then it should work,but i'm not sure about that