Or, as they say on board, a Norwegian piano. And it was also once a Viking battle cry. That's an order for everyone to show up on deck. Sometimes the jolly boats were then put into the water to tow the ship using oars. We were told that these funny-looking things were used to provide padding so that chafing would not occur aloft.
Research vessels use bumkins to hold specific pieces of apparatus.
This, believe it or not, was a term first used on boats to designate the galley deckhouse. In the 1860s, people in the U.S. started to use this word for the last car in the train. It's also used today to describe a too-generous posterior. All the way, then. On contemporary racing yachts, this is a big winch on the deck.