Hey guys this is kind of a last minute late night kind of deal. I've got a fisher freedom 240 dlx pontoon  1991 or 1990 I know for 100% certainty the motor is a 1991 mercury 90hp. I am going to assume the only location to mount a transducer is on the bottom right of that image I posted next to the speedometer. I have a hummingbird helix 7 g2 (non network) ice kit with the add on transducer kit xint 9 20 t. Before I go punching holes in the boat I was wondering if I could make a portable mount similar to a kayak would use. Say a pipe attached to a piece of wood to make this thing removable. Im torn between leaving the transducer mounted because this unit will be coming back home with me after this weekend. I honestly have no idea if there is a pass through that I can pass the cable through to get it near the console. The unit would be running on the portable 12v battery (9ah) and not a true marine battery ( though I do have an extra power cable for the future.   If I go the mounting route should the bottom of the transducer be below the pontoon or even with it? For those guys with units on pontoons will this thing work when under way or will the prop wash have interference? Don't have a trolling motor so it would be a slow troll.  Sorry for the rant, any insight on installing a transducer would be helpful.  Ive got all the tools and technical skills just weary because its my first install and don't want to make holes in the wrong spot with only one potential location.   ( pic isnt my boat just the same model.) 

Also wondering if i should put a spacer between the mount and that plate.

I have a bracket, which adjusts for length and it has a top "C" clamp with big wing nut and a bottom plate for attaching a transducer, which I believe I found at BPS many years ago to use on rental boats at various lakes. The plate on the bottom is configured in such a way that you could attach any transducer to it.  Probably made to attach of the gunnel of small boats and may not reach from your railing down to where it would be under water and not below your pontoons, where it does not need to be.

5 hours ago, OnthePotomac said:

I have a bracket, which adjusts for length and it has a top "C" clamp with big wing nut and a bottom plate for attaching a transducer, which I believe I found at BPS many years ago to use on rental boats at various lakes. The plate on the bottom is configured in such a way that you could attach any transducer to it.  Probably made to attach of the gunnel of small boats and may not reach from your railing down to where it would be under water and not below your pontoons, where it does not need to be.

Ya I would need something like a 6ft arm maybe more. thanks for the insight. I'm gonna buy once cry once mount this thing and just buy another for the next boat