True... a deliberate ram, unless you massively outweigh your target (see WWII destroyers vs. subs and motor torpedo-boats) is pretty much a desperation tactic by a captain who's made up his mind that his ship and crew are dead no matter what and want to cause as much damage as possible on their way to the hereafter.

My recollection, though, is that the law of the sea even back then was "when a ship sinks, whatever flag she sailed under, all nearby must render whatever assistance possible to rescue survivors," though our naval veterans may want to cross-check me on that.