La amikeca ŝipeto tuj subakviĝas
I would use boato instead of ŝipeto. While most people won't care, a boat is not just a small ship. In fact, not all boat are small; an Ohio class submarine is 170 meters long, but is still a boat. (I'm not saying it makes sense, only that sailors will complain if you call a boat a ship or a ship a boat.)
I would use renversiĝi instead of subakviĝi, as the boat is capsized instead of sunk.
(The artist does have cartoons where the rowboat does sink. As a further aside, about two-thirds of the way down, one of the cartoons has the penguins the same size in the first two frames with the capsized boat in the last.)