Depth transducer replacement

[wijnendael]

Hi all, have a faulty depth transducer and now located a replacement navman through hull type 26032. My question is the unit is fitted in a through hull removable unit (plastimo LT8f part number 40640) are these units sealed at the bottom or do i have to lift the boat from the water to replace the transducer, it looks like the top of the unit screws off and the transducer is pulled out. If the boat has to be lifted then looks like it will have to wait until the next time it has to come out before replacing as the crane charges are a lot more expensive than the transducer was.

 

[Dave_Seager]

As far as I can from pictures of that part number it looks similar to the Nasa unit that I have. It is not sealed at the bottom but can still be removed while the boat is afloat. They are normally supplied with a screw cap to seal the top of the tube when the transducer has been removed.

Some makes have a flexible flaps at the bottom to reduce the flow when the transducer is removed, although I do not think that they stop it complletely.

I remove my transducer occasionally for cleaning. You need to be ready for a rapid flow of water when you pull it out but, provided you are quick, you can fit the cap or refit the transducer with only a gallon or so of water coming in.

Incidentally, how do you know that your transducer is faulty if you have not removed it yet? There is not much to go wrong with them and they usually stop working because they are dirty.

 

[wijnendael]

Thanks for the reply, the screened cable on the transducer had a repaired break in it. Because it was not working when we bought the boat i checked the connection and found that the screen had corroded away right up to where it enters the transducer. As it is almost impossible to break away some of the epoxy where the cable enters i thought it would be easier to replace the unit and then try to repair the old one. The display is flashing "SOND" all the time which normally means a faulty cable or transducer. I will try removing the old one when the new one arrives and be prepared for some water coming in.