Gotta use AP at close range, shrapnel from a HE round could rupture a ballast tank.
Anyway...
We fired...
We killed the shark,It quit swiming (tail quit moving). but it acts like the Jap minisubs in the stock game, it can take unlimited damage and it just bounces around.
I'm still in this miserable storm, I've lost the Japs and have not seen any more fish. A few mermaids were reported by 3rd watch however.