I don't see any readily available item which will go in the existing through-hull hole. The choice seems to be a simple NASA instrument (the display part will fit in the space on the instrument housing) or something from Raymarine which will cost hundreds of pounds more. It seems that with the NASA one I would need to mount the transponder inside the boat and it is supposed to work properly through the hull.

Has anyone fitted such a thing to a P31 or got any useful advice about mounting the transducer inside the boat? Thanks.

I replaced mine a couple of years ago with the NASA unit, a more economical option. The display fitted existing cut out no problem. With regard to the transponder, it was fitted inside and works well. Replaced the speed unit at the same time , as both units displays were increasingly difficult to read.

Hope it helps

Chris

I was hoping it was going to be straightforward. I will go ahead with the NASA instrument.

Pat

Did you use the "In Hull Transducer Mounting Kit" which you can buy as an extra? Or did you bed it in mastic or what? I gather there must be no air bubbles between the transducer and the hull.

Thanks, Pat

It was done by Upson’s yard, as they replaced the speed log unit as same time, as removing the old log unit’s through hull fitting kit and cutting new holes in the hull is a job I leave to the professionals!

A mounting kit was used, I have a feeling they put oil in the tube for the transducer to sit in, I would go and check but have just arrived in Caribbean for a couple of weeks.

Hope this helps

Chris