OK, so I was sent to the Marshall islands to patrol and sink merchants. I get there with 80% fuel to spare, and it's quiet, so I head off towards Saipan. There were some task forces around but I didn't see them, so I decided to avoid the airbase and went into Guam instead to blow some stuff up.
I tear a small merchant in half with two hits, then I concentrate on a big juicy tanker. Fire tubes three and four, good hits low on the hull. Target buring, alls good... Fire tube 5. hit about one foot above the keel. Fire tube 6, perfect keelshot. I turn to something else and blow up a large modern cargo ship with 3 shots from the stern tubes... but the tanker hasnt sunk! I fire tube 10 at it, again hit just above the keel.
I turn around, engines stop, and wait two hours. Fire tubes one, two and three at it, all hit, at least one keelshot... nothing. not even any list. I made my quota by gunning somethingelse and went home!!
8 hits, at least 2 keelshots, and the tanker was still there, alive and well!!! WHAT THE ****!!!!