The depth sounder on my 470e started showing inaccurate depts, and would sometimes not show the depth at all - now it is not showing anything at all - has any one come across a similar problem or has any idea / hints on how to fix this?

Thank you

I find sometimes the issue is with the earth, if you remove the log every time you come back, to prevent squatters moving in and stopping it from rotating the next time you board, then there's always water present whilst switching over.  This eventually corrodes the wiring and the earth is are bare wires not protected by a plastic sleeve like the others.

I suppose it depends on what layout you have with the front cabin, ours has the double against the forward bulk head with the on-suit heads to port. The transducers both depth and speed are located just in front of the bed, so approximately 600mm forward of the mast about 0.7m below the water line.

To get to ours you need to lift a floor board.

My original Flexofold prop pitted, bearing in mind that the standard one is undersized as Yanmar/Hanse had a deal to ease stress on the Sail Drive.  This was due to galvanic corrosion from the housing development the other side of the river, being earthed to the metal piles of the marina.  The SD only has two anodes so I ran an earth lead from the block of the engine to the stern and connected another anode that I manually lower over the back when NK is on his home berth, I wonder if it is similar with yours?

No, tanks (fingers crossed) have been fine, what I do have is occasionally rain water seeping down the mast, I leave a cloth round the bottom of the mast in the master cabin and so I can feel if it has leaked.  I also cut a hole in the floor just in front of the mast so I can get my arm in and mop out any water that can collect at the mast base, otherwise it runs back to the battery/pumps/tank area.

I replaced the rubber gaiter when I had the mast out (10yrs ago), there was a split in that and make sure that the two bottle screw type fittings either side of the mast are tight.  The last thing to check is your rigging has it loosened allowing the mast to move slightly, although this would likely allow sea water in when sailing, if water coming over.

I have just one thru-hull fitting for a transducer with 3 features: depth/speed/temperature.

It was replaced once as the depth failed and currently the speed doesn't work but I guess is a growth issue. I'll wait until the next haul out as I don't want salty water coming in.