Before you toss out your thru-hull depth transducerdepth transducer...

[phorvati]

try to replace the cable connector. Transducer cable looses contact at the connector, especially if there was any tension on the cable.
My thru-hull depth transducer, part of the datamarine Link 5000 system was showing fault 01 for about two yeas now. I had originally installed it in 2004. So i was a bit upset that it already stopped working. Bought a new one from Datamarine, when it dawned on me to clip off the RCA connector on the end of the cable and crimp in a new one. It started working again. So now i have a 160$ spare.

[S/V Alchemy]

RCA connectors are cheap, but are cheaply replaced, so that was a good instinct.

I have come to the conclusion that continuity testing is one of the better skills to have on boats, wet and corrosive places that they are for wiring. Right behind that is knowing how to mount cabling to avoid friction, tensioning, induction issues and "dampness mitigation", like drip loops.

I'll bet you have fun in a C&C 38. It's still a pretty hot boat in a seaway.

[phorvati]

Thanks, I try.
In my experience, connector/fuse/wire continuity accounts for 99% of perceived failures in marine electronics. We end up buying expensive electronics components where in most cases it just takes a little soldering or crimping and patience.
In the case of Datamarine transducer, transducer end is sealed so it made impossible probing for continuity.