I use to race F5D pylon planes in the early 2000s. There was a guy in Australia that made 1 blade props and I tried a few. The first thing you will notice on a 1 blade is they are a lot louder. I found them to be as fast as 2 blades but not really faster. Because you only have 1 blade in the air, you could get away with using more pitch. That's how they can be faster. But they were incredibly hard to balance so they could spin up to full potential. Also, a 1 blade prop was a lot of money, $75. versus $4.00 for a 2 blade APC. In F5D you really needed to be able to adjust the pitch according to weather conditions. APC props could be adjusted in pitch by using a heat gun, so the fastest guys used those and not too many 1 blades flew in competition, even though we all had some in our box. The 1 blades had a counter balance of lead on one side which was hiding under the spinner. I don't see how you could make a good prop for a boat but I'm sure it could be done. But with props half out of the water, I see a 1 blade not working as well for heat racing versus a 2. They could possibly work in a saw boat because a 1 blade loads the motor less, but there very difficult to balance properly and hard to make. It would take some dedication to get one to work.