Access to water speed sensor

[EarthBM]

Mine periodically clogs with something then starts working again after a few miles. On a Hunter 40 I sailed once the owner removed the speed sensor after every sail, plugging the thruhole with a dummy, flooding the bilge each time. Is there access to the water speed sensor from the cabin on DF 35?

[parkhouse]

If your Df35 has the same layout as the Df1000, the speed/log transducer is a bit port of centre in the compartment astern of the freshwater tank. There are members of the Df forum who remove it and replace it with the 'plug' every time they finish their sail but I suppose it depends on the amount of weed in the vicinity of your mooring/marina.
Mike Paterson, Df1000-34 Champus

[parkhouse]

One more thing, the design of the transducer is such that there is a valve which automatically closes as you pull it out and opens again to allow the 'plug' to be inserted. A bit of water gets in but certainly not a flood.
Mike Paterson, Df1000-34 Champus

[Steve B.]

One more thing, the design of the transducer is such that there is a valve which automatically closes as you pull it out and opens again to allow the 'plug' to be inserted. A bit of water gets in but certainly not a flood.
Mike Paterson, Df1000-34 Champus

Mine doesn't have that valve. It sure would be nice!
Usually what fouls mine are tiny shrimp or other critters.

I've dreamed of some kind of way to blow the paddlewheel with a quick shot of compressed air from the cockpit !

[tpaliwoda]

I am also from the school of "pull-out-the transducer". Mine is a B&G unit that has the stopper in it. Only a few ounces of water come in when I pull the transducer and put the blank plug in.
If I didn't it would be fouled in a week! We have to many of those shrimp like creatures by us! They also make a real annoying sound at night, but that is another subject.

Did you try coating the paddle with the transducer anti-foul paint?

[penryj]

In the Gulf, a week in the water would find the whole unit pretty much welded to the hull due to the growth.
Its not so bad here but I still take it out. If you have your wings folded on the DF35, the main hull is lifted out of the water even more so the inflow is minimal. I usually wrap a rag around the intake and this mops up most of the water.

[EarthBM]

In the 35 the speed sensor is just in front of the galley sink. Measuring the water flow in scottex plies, I'd say about 30, more than I expected.

The speed sensor was thoroughly fouled up with sea weed and critters, I cleaned it with more scottex and visibly it was ok. Yet after I plugged it back in, water speed was consistently 2kt below GPS speed. There sensor itself had no direct connection to the wire, I imagine the rotation is transmitted via magnets. Is there anything I did wrong?

[Steve B.]

Around the North end of Puget Sound, there's a lot of current.

[EarthBM]

Around the North end of Puget Sound, there's a lot of current.

I know Steve, but that was in all directions...

[Double Horizon]

Is there anything I did wrong?

Maybe it is not aligned properly. There is an arrow or triangle on the top that should point forward. Or maybe there is something fouling the hub of the paddle-wheel. Try cleaning the axle with dental floss and make sure it spins freely.

[EarthBM]

Had a diver clean the bottom this morning. He found another transducer on the sb side of the sail drive. Sure enough it was clogged with hair wrapped around it. Don't know why there are two transducers, another riddle to solve.

This thru hole had that flap valve preventing the flood. Definitely a good solution.