Found a scrap of paper with RPM readings taken by a $25 hand-held laser tachometer. Fixed three-blade Michigan sailor prop, Universal 5432.
5 knots, 1875 RPMs
6 knots, 2275 RPMs
7 knots, 2815 RPMs
The readings on the boat tach are about 100 RPMs higher than these laser readings.
5 knots, 1875 RPMs
6 knots, 2275 RPMs
7 knots, 2815 RPMs
The readings on the boat tach are about 100 RPMs higher than these laser readings.