Mys Terry wrote:

I bought a cheap Humminbird and set that "transom mount" transducer in
a blob of clear silicone in the bottom of my boat just ahead of the
keel and it works just dandy, despite all the warnings about not doing
exactly that in the Humminbird instructions.

Just make sure the blob of silicone doesn't have any air bubbles.

The fish finder my wife bought for me came with a transom
mount transducer, _and_ instructions about how to mount it
inside the hull if you did not want to do the transom mount
thing.

IIRC the method was similar to what you did, although there
was a section about making a temporary mount that you could
slide around before you put the glue in place. That was to
make sure that you selected a good location without voids,
etc. for the transducer to shoot through.

Since I was mounting it on a power boat with only the ski
locker and engine compartment accessible for interior
mounting, I put it back on the transom, and ran the cable
through a hole high above the water line. If I were to add
a similar unit to my sailboat, I would most certainly mount
the transducer inside and shoot through the hull. The only
drawback is reduced range, and the transom mounted unit
already sees down to over 200'.

Don W.