Joern,

It certainly is possible that the reloads were carried off by a fishing net. However, given the empty bow tube, I think it's more likely that UC 30 didn't have any reloads on deck when she was lost. Why wouldn't you reload the tube if you had a torpedo available?

I'll take a look at some KTBs over the weekend to try to determine the typical number of torpedoes carried for a HSF boat operating off the Irish coast.

Best wishes,
Michael