There are also documented cases of early days in the war of U-boats taking torpedoed boat survivors on their decks (or towing life rafts) to a near by port. This practice was however short lived as allied aircraft took the opportunity to strafe these U-boats which inevitably both resulted in German and Allied seamen casualties.
It all got nastier from then on in……..
(Ooops - *Uncle Goose* correctly mentions this already -
http://en.wikipedia.org/wiki/Laconia_incident)