that's sorta like a pirogue with blunt ends

Yes... probably the best way to describe it for Americans (who've been to Louisiana and Venice) is to say that it's a blunt-ended pirogue that's operated like a gondola (not with the paddle -- that's cheating, unless you're using it to recover a pole that's got stuck in the mud and left behind). It's (AFAIK) peculiar to Cambridge and Oxford.

Peter