BuscaBrisas has a 5 hp Honda for aux power. After trying out the standard prop for a while, I decided that the engine was unable to reach full rpm's at full throttle, so I swapped to the lower pitch prop. That helped some, although I think the pitch could have been even lower. This from the archives: "When I bought my Honda a couple years ago, there were two different props for it: 7 7/8 x 7 1/2 and 7 7/8 x 6 3/4. (Diameter x Pitch). The 7 1/2 pitch prop was standard. With it, the engine rpm maxed out at about half-throttle. I bought the 6 3/4 pitch prop after a year and with it the rpm's max out at about 3/4 throttle, so the 6 3/4 pitch prop is a better match between the engine and the load it's pushing and more engine power is being transmitted to the water. That doesn't translate into a particularly noticeable increase in speed since resistance goes up quickly in relation to speed, but it does mean that the boat will be able to power against a stronger headwind. An even lower pitch of, say, 6 1/2 or maybe 6 1/4 for the Honda would have been better" Tod