Rick, it could be that the boat was permanently deformed by sailing in the Bermuda triangle. A simple residual 10% time/space compression distortion would leave the boat, um, 30.6 feet long now, with the engine operating 10% too fast simply because the ring gear had now been permanently reduced in size by 10%.
That kinda stuff happens all the time, right? <VBG>
So, using a new tape measure that's never been on the boat before, first we measure the boat...<G>....