Electrical Wiring and installing a new transducer

Norm Magnuson

Contributing Member
I am looking at

Ancor Marine Grade Products 121525 Duplex Cable, 16/2 AWG (2 x 2mm2), Flat - 250ft for wiring I a new fuel gauge from tank to gauge. Will 16/2 work or should I use 14/2? I also will rewire all lights and all electrical with this wire.​

Need to install new fish finder transducer on my pontoon below the bottom pontoon. Which is a better adhesive to use, 3M 5200 Fast Cure or Marine-Tex?

Thanks in advance!
14 gauge is likely overkill for the fuel gauge but a choice for most everything else on your list...just make sure you use good terminals and a proper crimper.

I'd be inclined to use the 5200 for the transducer....you didn't say what it's made of so figure that out and call 3M's tech support line and see if a primer is needed...
In pricing 14/2 for 250’ was $ 11.00 more than 16/2 at 250’. I’m going to go with 14/2.
The transducer has a plastic plate which will mounted onto an aluminum pontoon. The transducer then is attached to the plastic plate. It will be about 1” to 2” below the bottom of the pontoon, I believe. The depth finder/fish finder is a Hummingbird 700. I’m concerned about the drag or pressure the transducer will bear where and how it is secured to the aluminum pontoon.
Thanks for your reply.
the nicest setup I have seen have a mounting bracket welded onto the aft end of the pontoons...near the lower edge but just above it...that allows mounting the transducer in a solid flow of water but allows the transducer to pivot up if the trailer bunk interferes...

it also provides a flat surface (similar to the transom on a traditional monohull) for attaching the transducer's bracket...vs the typical hemispherical aft end of a pontoon.
Thank you for your knowledge and experience. Facing to the front there is a bracket welded to the back of the left pontoon. It comes out about 2” to 3” then straight down about 3” and then back to the pontoon. If I attach the plastic bracket and then secure the transducer, it may or not be below the pontoon bottom. Also under speed, I’m not sure if the transducer will be under water or if it is, it may be in turbulent water and not sure if I would have water depth readings. The pontoon is in the water at the marina so it’s hard to guess until I pull it out and park it in my driveway for a few days. The current transducer was attached on the right pontoon in the center, just below the pontoon bottom. Does the transducer need to be below the pontoon or equal to the bottom of the pontoon? I’ve always had boat’s/yachts where I had through hull fittings.
Again, thank you.
I'd say call hummingbird's tech support to get their view...just to be safe.

I put them in so that the transducer has a solid (non-aerated) flow of water over its bottom...usually below the hull's bottom but not much...maybe an inch worst-case.