DIY Transducer Arm for Kayaks

Since installing my Lowrance X-4 fish finder in my kayak, I’ve questioned it’s accuracy, especially when marking fish.  When moving, I would mark a LOT of fish at the surface, which I knew was wrong, but I was unsure whether that was due to the duct seal used to mount the transducer in the hull, or perhaps turbulence from the hull cutting through the water.

I had already decided I wanted to add some YakAttack GearTrac to my kayak for use with the GoPro, rod holders, etc.  I chose the SL version, made from a lightweight composite, mostly for it’s affordability.  Since I was adding this, I also decided that it was time to try mounting the skimmer transducer onto a folding arm.  The concept for these arms is very simple, so why not try and do it myself!

Parts Needed

Cut two lengths of tubing.  The first is to move the transducer away from the side of the kayak.  The second is to move the transducer down into the water.  Both of these lengths will vary by kayak and how far you wish to have the transducer into the water, but should be very easy to measure for your application.  Once the two lengths are cut, drill a hole from top to bottom near one edge of the piece designed to move the transducer away from the kayak.  This will allow the MightyBolt to pass through and mount the arm to the kayak.  These bolts are 1/4″, so your hole should be 5/16″ or 3/8″.

Test assembly on the workbench.

Test assembly on the workbench.

Now mark and drill a hole from side to side on both pieces of tubing.  Theoretically, this hole should be 3/8″ from the top, bottom, and outside edge of the tubing to ensure that the edges of the two pieces are flush when folded or when the transducer is deployed in the water and the two pieces are perpendicular.  Attach the two pieces with the long 1/4-20 bolt and threaded knob.

Closeup of the notch cut and filed to snugly fit the Lowrance Skimmer Transducer.

Closeup of the notch cut and filed to snugly fit the Lowrance Skimmer Transducer.

Finally, attach the transducer.  The Lowrance skimmer transducers mount very nicely in the inside of the 3/4″ tubing, but your mileage may vary if you’re using a different transducer.  This is just trial and error, but using a small saw and file, you should be able to mount the transducer securely.  Cutting an additional notch may also allow you to fish the cable through the inside of the tubing rather than having to zip tie it to the outside.

I’m very pleased with the results from this move to the outside of the boat.  Readings seem more accurate and I now have a valid water temperature reading, something I was unable to get shooting through-hull.  It’s also very easy to flip up out of the water if I need it out of the way for fighting a fish or beaching the kayak.

First trip with the new transducer arm.  Westwood Lake in New Castle, IN.  It worked like a champ!

First trip with the new transducer arm. Westwood Lake in New Castle, IN. It worked like a champ!

4 thoughts on “DIY Transducer Arm for Kayaks

  1. Pingback: Finally! My first kayak tournament is in the books! | Geek-Fish

  2. Like how the arm folds away after! Did you notice and drag when paddling due to the mount on the side?

  3. For a neat perspective, mount your GoPro on the arm focusing on the bottom of the boat. It makes a neat shot as you’re paddling through the water.

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