The speed vs engine rpms run was done to test the calculations I did when sizing the prop. As with the engine install I did all the calculations to decide on the proper prop size and pitch myself. The plot below shows my calculated boat speed versus engine rpms in red and my measured results in green. I am satisfied with the result.

One area I did goof up on for the calculations was fuel consumption. My calculations said I should have consumed about 0.38 gallons per hour at 6.5 knots. Actual fuel consumption worked out to 0.315 gallons per hour at 6.5 knots. I can live with that sort of error