david: don't replace the knotmeter unless speed-over-water is really important to your sailing. a GPS will give speed-over-ground information that is 'good enough' IMO. having the hole glassed would be a good repair for the off-season. if you have a local chandlery taking photos of the transducer and showing this to the 'professionals' may help in finding a modern unit that may work with the 'older' thru-hull. as you already have a hole for a transducer if you replace the old with a new just get a unit that uses an opening of the same or larger size ... at least that way you don't need to make a smaller hole. a 'no holes' in boat option is to have the transducer opening glassed and then get a depthsounder that will read through the hull. dave scobie M15 #288 - SCRED visit Scred's www-site - http://www.freeweb.com/m15-named-scred --- On Tue, 3/10/09, David C. Patterson <davidcpatterson@msn.com> wrote: I hope someone on the list can help me with this: When I got my 1985 M17 last year no electronics came with her, except for the old radio epoxied to the overhead! There is a depth sounder transducer through the hull, and a knotmeter wheel also. Lots of wire, but no identification of make or model that I can find so far. The old owner has been non-responsive. I would love to use them as is, which is to say I am very leery of removing them. But how do I match them to current electronics? Has anyone worked this kind of thing out before? And, yes, I have run aground when I wasn't wanting to. Just a few times. Thankfully the board and rudder both can be raised.