Whale factory Ship?

[Sailor Steve]

I'm not sure. Even sinking a neutral or friendly ship should show up in the patrol log.

I'm sorry to derail in the very first reply, but you do bring up another beef I have with the game:

Originally Posted by GJO

...so submerged while the damage team went about their repairs.

Any shell hit that could damage your engines would also leave a hole in the pressure hull. You should not have been able to dive at all, for the rest of the patrol.