So far during testing today, I have managed to sink only 1 out of 9 targets using 2 torpedoes.
Have waited about an hour in each case. They list very heavily but go no further.
Is this as designed?
Just seen your point about the weather, that may have something to do with it. My shooting range is set up dead calm.
Will try some more testing in 5-7 ms weather, and get back to you.