No sonar contacts either prior to surfacing, eh? You did not take any damage from the Sunderland attack, but did the lights flicker, or you get any shake? Is there a "dud" sound in the mod from when you attacked the Granville, or did the torpedoes under-run the ship, and not detonate? Do you have a radar signal detection device on you boat? I have not played much beyond my encounter of a convoy last week, and I'm still in the process of attacking with no issues thus far. I'll be busy with other chores until mid-week sometime, and I hope to report back to let you know the outcome.