Fouled knotmeter sending unit
Bill– I am thinking the knotmeter paddlewheel could be poorly located. If it is in the wrong place, normally occurring turbulence and low-pressure areas beneath the boat under sail will cause erratic or non-existent readings. It should be just forward of the keel and as close to centre as possible. Places to avoid are immediately beside the root of the keel, especially toward the after edge, directly beside the prop strut, directly behind anything, and maybe too close to a big through-hull opening. Does it work better under power than under sail? Does it work better heeled to one side than the other? –or heeled than flat? Does it leak? I should have asked if it's electronic or mechanical but I'm assuming electronic. This suggests something else– if it works better under power you may have an electrical fault that needs more oomph in the charge. Try metering the wires to see how it is under power and not. Also if it's metal the axle pin in the paddlewheel could be corroded, loose, or missing, and maybe the plastic thing under the boat is missing blades or just plain BROKEN! Of course seeing as you are from Babylon you may be precisely right in your guess about fouling matter. As I recall that bay is like lobster-pot city!!! Perhaps try one of those silly stick-on-the-transom things speedboaters use, even temporarily mounted on a board, to see if it's the location. At least that type does not foul easily. Or go to a propeller-type unit which might even fit through the same opening in the boat. I have seen even aluminium beer-can pull-tabs foul a paddlewheel. J Cherubini II JComet@aol.com
