"S.O.S." is one of the better Betty Boop cartoons--mostly because there's no singing and the film is a bit insane. However, it also is very dark for a cartoon if you think about what is happening.
The cartoon begins on a cruise ship. A storm is knocking it about and passengers are hopping off right and left. Eventually it sinks and the only survivors you see are Bimbo, KoKo and Betty Boop on a raft. Soon a ship arrives to rescue them but their excitement is short-lived--it's a pirate ship. After locking up the guys below, the crew seems rather intent on raping Betty (perhaps I am reading this into the film). Eventually, Koko and Bimbo escape and the three are chased about the ship--only to outsmart the pirates and send them all to their deaths. As I said, this IS a very dark cartoon! Despite being so dark (or perhaps because of), the cartoon is entertaining, has a wonderfully weird style and did make me laugh. Plus, like all Betty Boop shorts, the animation is amazingly good. Well worth seeing.