Hi, Mark Not a stupid question at all. It's a matter of trade-offs. You would in fact get a better signal if the transducer were in direct contact with the water; anytime there is a change of medium there will be a bit of signal degradation. It would only become noticeable if the readings were very deep and not of significance for us. Recognizing that, the fishfinder folks have the shoot-thru-the-hull pucks which don't really have any provisions for mounting in a thru-hull. That helps keep the cost down and saves having a hole in the hull. Tod M17 #408 BuscaBrisas <=has two cockpit drains below the waterline that I wish weren't. Tartan 26 #30 Pretentious <=project boat will have no thru hulls anywhere near the waterline. -----Original Message----- From: montgomery_boats-bounces+htmills=bright.net@mailman.xmission.com [mailto:montgomery_boats-bounces+htmills=bright.net@mailman.xmission.com] On Behalf Of Mark Paxson Sent: Wednesday, November 16, 2005 10:57 AM To: montgomery_boats@mailman.xmission.com Subject: RE: M_Boats: Re: Pirahna Max 15 installation I'm reading a lot of ideas on mounting the transducer and forgive me if what I am about to ask is taboo but what about drilling a small hole through the hull to mount it outside and sealing the hole good? I believe there is no such thing as a stupid question, and hope I'm not proven wrong. Mark A. Paxson -----Original Message----- From: Norm Bundek [mailto:nbundek@earthlink.net] Sent: Wednesday, November 16, 2005 9:33 AM To: montgomery_boats@mailman.xmission.com Subject: M_Boats: Re: Pirahna Max 15 installation Rick, The temperature was moving around several degrees as I moved around. I don't know how accurate it was, but it did seem to have some sensitivity from the time it was turned on. Norm _______________________________________________ http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats _______________________________________________ http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats