That's certainly true--oars are by far the most common configuration for human powered boats. I was thinking more about human powered boats that set speed recor

That's certainly true--oars are by far the most common configuration for human powered boats. I was thinking more about human powered boats that set speed records, e.g. the Decavitator https://en.wikipedia.org/wiki/Decavitator https://en.wikipedia.org/wiki/Decavitator A lot of this might just be because Mark Drela, who was involved in the design of several of the aircraft and boats on this list, is a cyclist.