On my last patrol (NW of Ireland, december 1934) I managed to tear out a large troop ship out of a convoy, got hunted for a long time, raised periscope when the escort was gone and lo and behold: a lone Aquitania, stationary and listing, right where the convoy had passed before.
This was my second Aquitania in this career, the first one I sank off Gibraltar 1942-ish.