THE smoke problem seems to be licked. Mike the Mechanic worked on our boat most of the day today to figure out what the problem was. In the end, it turns out that the cooling water impeller had shredded itself (probably when we picked up some debris on the intake, which caused excess suckage), and distributed pieces all through the cooling system, clogging the cooling system and causing more steam than normal. We weren’t seeing any overheating, but we would have done shortly. Now we know that on this engine, white smoke should mean check the impeller.
This didn’t fix the lack of power, but we now know what that is: the prop is overpitched. Basically, the prop is trying to push too much water aside, which doesn’t allow the engine to reach its max revs. The symptoms are identical to fouling the prop. We will leave it as it is for now, since we can get 6.5 knots, but when we haul, we’ll get it repitched–we should be able to reach hull speed (about 7.5 knots).
We will attempt to head south tomorrow.