The speedometer on my F25 became completely encrusted with zebra mussels over the course of last season. I’ve heard of “optical flow” sensors, which is a camera and specialized chip that looks at what the camera sees and translates that into motion. That seems like a reasonable way to have a speedometer that doesn’t get ruined by zebra mussels.
Has anybody tried one? Hang it off the stern on an outrigger at least 80mm above the water’s surface.
Hi Russ
I have not tried an optical log but am very impressed by a nasa electromagnetic log I fitted recently. It needed a slightly larger through hull hole than my nasa paddle wheel but the version I bought has the same electronic interface as the paddle wheel. I bought this as the paddlewheel log would jam after a few days in the water and was pretty much always out of action.
It seems very accurate, I set it up using gps on a lake, so no tides flows to worry about, it has a potentiometer to calibrate it. The only issue I found was a slight difference in readings on port and starboard tacks when heeling of a one or two 10ths of a knot.
It has a smooth flat surface that seems to be resistant to growth. I found none after a season on fresh water.
Hope this helps,
Chris