Re: transducer mounting: is inside the hull mounting a bad idea?
Not a problem if you do your homework.
Easy way to test is to put it in a bag of water.....learned that on here....I used to do as j said; put some water in the bottom of the boat, but the bag idea has merit. You can use some duct tape to tie things in place till you get your readings. Tape the bag up around the cable to seal it.
For reference, in calm water, put the ducer over the side and take a reading in as deep water as you can find. If there is structure, like trees or something besides the bottom, so much the better.
Then put it in the boat where you want to mount it and compare readings. Moving it about may help also. If you have a gain control, reducing it till a target is just visable will really tell you the difference when you move it inside and have to crank up the gain to see the target. If you normally boat in shallow water (50' or less) I'd say that gain isn't all that important.
If gain is really obstructed, like if you do have a double hull, moving around might locate an area where there is just one hull thickness. Course material is important....if solid alum or glass not a problem. If a cork or air core, gotta make other arrangements as pond tunes mentioned.
Important thing is to use a good epoxy and get the bubbles out between the ducer and the hull. Air is not a good conductor of sound waves. Also lightly sand both surfaces and degrease them prior to installation.
I know the other supplier of sounders has a web site and they recommend an epoxy, but I've mounted several and was not picky about epoxy....just careful to mix it slowly so as to not introduce air into the mix.
HTH
Mark
