Thanks for the advise on mounting the transducer (guess that the correct term; not transponder). Guess I need to ask if there is a customary way to mount the transducer on a pontoon that will work but prevent the transducer from getting caught on weeds, branches, and whatever? Its pedestal mounted to a bracket on the pontoon now and gets knocked or pulled so that it points up at the sky. If I were to tighten the mounting screws I risk damaging unit. Help ya'll!!!! I would like to have the fish finder work long ecnough to learn how to use it.

Unfortunately, what you describe is a "fact of life" for transducers mounted on the outside. That's why most bass boats have them mounted inside and "shoot through" the fiberglass.

That's not an option on your pontoon boat, so the only thing available to you is to tighten the hardware to the point that it takes a pretty good hit to tilt it up (but not so much that you run the risk of tearing the screws out of the mounting point).

You should be able to tighten it enough that weeds and small limbs won't displace it, but larger stumps/logs will.

C.

Well, could a fiberglass mount be fabricated and mounted to the pontoon? Could I cut a hole in the bottom of the box mount and fiberglass the transducer to the mount? If done right it would produce a snagless mount and be shooting through the fiberglass bottom of the mount. Maybe I'm wishing for the impossible, but it sure beats jumping overboard to adjust the transducer.

Sorry, but I can't advise you about fabricating a fiberglass mount for your pontoon. No doubt, it is possible to make such a device, but whether it will improve your situation remains an open question. Anything you devise that will itself be mounted on an exterior surface of your boat is likely to incur damage if you happen to ride over a log or stump or similar, and in doing so may damage the surface you have it mounted to (pontoon?).

If you try to make such a devise - good luck with it!

C.

My 'toon has a box on the back end of one of the tubes that has a pump for the livewell. I've drilled holes and thru-bolted a couple of layers of plastic cutting board (cut to fit) on the box. I then screwed my transducer into the plastic. I did this because I seem to switch fishfinders every few years and I didn't want to drill hole after hole in the only available mounting place.
Sorry, got side tracked... anyway, I also made a plastic 'plate' for the bottom of the box that would reduce the profile the transducer presents to objects in the water. I've had no issue with the trasducer kicking up, but maybe mine's too tight.

Dang, next thing ya know grandpa will be wanting to mount an electric troll motor on the bow of that pontoon boat... ...turn it into a real fishing machine a la DJTripleR...

DUH

Actually, he next problem I was going to ask about was anchoring. What type of anchor and how do you store it? I still have a bow mounted crank dealy that I bought for the old boat but it doesnt see to be adaptable for the pontoon boat. (Ya'll are welcome to make fun if ya want. I've never had a new boat before, never had a pontoon boat before, and never had time to fish much in the last 15 years, except from the bank. And I did hold 5 out of state licences at the same time)
I tried the concrete in a five gallon bucket but it won't hold in the wind and I bout have a heart attack trying to pull it up.

Grandpa, if you wernt so far away id bet between the two of us we could rig you up. Is there a place you can bolt a piece of 3" angle iron on to mount the transducer?

There is an aluminum "box" like glenwill was talking about welded to the back of the pontoon. The transducer is screwed to the bottom of the "box"; which is very convenient for kick up.
It hangs just a fraction of an inch below the pontoon bottom. Now I got another dumb idea using glenwills plastic cutting board. Why can't I enclose the transducer if a plastic cutting board or fiberglass "box" and attach the whole thing to the existing aluminum welded "box". The transducer could shoot through the plastic like the inhull mounted on bass boats. The enclosure would ensure no cavitation noise. Being enclosed would eliminate the kick up. (I think) The worst it could do is bend the aluminum box welded to the back of the pontoon and I can straighten that back out. The whole idea is to get the transducer in an area that it wont snag on weeds and brush.

Grandpa
I have a barge to and my biggest problem with the transducer is drifting back into stumps and breaking it. The idea of fiberglassing it into a box and mounting the box sounds feasable to me, if you do it and it works let me know..