in Hull transducer performance

[baldrick1]

I own a 1982 lm30 and currently have what I suspect maybe an original an echo sounder with a through-hole transducer. I'm considering fitting a NASA duet in Hull echo sounder transducer ( with a through hull non paddlewheel electronic speed log ). Being a 40-year old boat I suspect the hull thickness is a lot thicker than its modern equivalent . I would appreciate any comments from those who have fitted in Hull transducers.
Thanks
Paul Dorset

[paulsailing]

I have an Lm27 with a NASA through hull echo sounder - seems to work well. Have yet to try a non paddle wheel log.

[bobevans]

Be aware that the electronic version of the NASA log requires a larger hole for the transducer. The paddle wheel version has the smaller hole which is I believe the standard size of older transducers. I had a Stowe log which I have replaced with the paddle wheel NASA with no problems on my LM27.
Bob

[seekinglm]

Hello Paul,

I have a 1975 LM27 (Hilda May) which had a Raymarine depth transducer fitted when I bought her. This year I added a fish finder and thought I would start by experimenting with the transom mount transducer it came with: I stuck it to the inside of the hull on the starboard side using blu-tac. It was intended to be a temporary measure, but worked so well that I have left it like that. It generally agrees quite closely with the Raymarine instruments, which is reassuring, although it seems to struggle a bit more when there is less than a metre of water under the boat.

As for the hull thickness, I fitted a bow-thruster over the winter and kept the pieces of hull I cut out. From memory I think they were around 12/13mm thick - which was a bit thinner than I was expecting (I believe that others have said the hull is around 15/16mm thick).

I should think that your transducer will work well through the hull.

Regards

Andy