I fish pretty often out of my grandfathers pontoon and wanted to put a fish finder on it. At the risk of sounding stupid, I was curious how to mount the transducer as the only part of the boat that is in the water is the pontoons themselves.

Suggestions?

I assume you have a aluminum braces that go from side to side,can

you fab a aluminum arm and place a 90 degree bend and attach it to

the brace near the back and mount the transducer on the bottom

of that.Cabelas has some premade ones for under 40.00 that i

am taking about.

All you have to do is get a piece of marine ply wood and mount it to the frame of the pontoon.  Be sure it reaches the water and mount the transducer to it.  The best aluminum boats in the world (Lund) come with one so you won't have to drill holes in the transom.