Inexpensive fish finder

I haven't popped in for some time, But as a few know I got a 29ft. sailboat at the begining of the year, the Electics were all ruined and need replaced, I'm very low on funds as I paid for a years dock fee at Salmon harbor,in winchesterbay and Also need a Chartplotter/fishfinder, SO if anyone who has an older one thats laying around after they upgraded and maybe have one to sell cheep? I'd really appechate it. the Transducer on the sailboat works I wired it to my old Fishfinder from my Lil blue Sink,so at least I can tell how deep the water is and I see a fish from time to time too lol.

Right on. I'd like to see some before and after pics when you're all done with your boat. I think that's a pretty cool project you've got there.