Speed log transducer

[davidc]

The raymarine log on my SO29.2 is not working when sailing or motoring.
I have freed it up both in the yard and using dive gear under water.
It appears to be turning freely by hand-but does not read when under way.
The speed indicator reads in the cockpit when the transducer is spun by hand under water.
I had the same fault last season and paid particular attention to it in the yard- cleanig it thoroughly and using a special aerosol anti foul instead of the thicker hull anti foul.
Any ideas anyone? do I need a new through the hull transducer?

[flightdeck]

Davidc,
The fact it works when spun by hand would indicate there is some kind of signal coming thru, I take it the arrow on the transducer point's to the bow (had to ask) could somebody have been playing with buttons on the head-unit and changed the calibration by accident, maybe check up in the manual, see if there is a factory reset mode.
Cheers

[so40gtb]

I had mixed results in testing my transducer two years ago. Initially, it seemed to indicate speed at the knotmeter when pulled out of the water and blown on. A few months later, that didn't work. I ordered a new transducer unit, installed it before springtime launch, and have had no issues since.