This happens to me too. If you have taken damage during a patrol you get the sound of glass breaking and the dials look broken each time you subsequently load a save from that patrol. As far as I am aware it has no further detrimental effect on your u-boat.
Nemo
__________________
"I'm afraid there is no disguising the fact that King's obsession with the Pacific and the Battle of Washington cost us dear in the Battle of the Atlantic".
Sir John Slessor GCB, DSO, MC, DL
AOC-in-C Coastal Command RAF
___________________________________________
|