Closest I got and got home was hitting a mine in the Thames estuary, this blew off the entire conning tower (location destroyed) ruined one diesel, both electric motors and all torpedo tubes (this was type II boat). the boat sank to the bottom but it was shallow enough to sit there, fix the flooding and surface by blowing ballst.
it also cost me 80% of my diesel fuel. I got the boat back to wilhelmshaven by hugging the dutch coast all the way at 4 knots.
I also once sailed a Type IX back from North of Scotland with the conning tower destroyed and both flak out as well, thankfully the diesels were all right so it was maximum speed all the way back.
It can be done, but it's not what I'd consider a fun trip
