I have received a lot of questions on how I fabricated the rear transducer arm for my 2012 Ride 135. There are a few elements I may update with this setup in the future, but I really like the way it works as-is. In the past I have used transducer arms that hang over the side of the kayak (like this DIY removable fish finder project) or installed the transducer so that it fires through the hull. This new setup accomplishes a couple things: 1) water temperature is accurately measured and 2) the transducer is protected, out of the way and creates minimal drag. Having the ability to rotate it up and out of the way also makes things easy during transport.
Poly Cutting Board (Walmart, Target, etc.)
Aluminum Flat 1/8 x 3/4 x 3' (LINK)
1 Rubber Stopper 3/4 x 9/16 x 1 Lowes Item # 139548 (LINK)
Package of ¼-20 x ¾ SS Oval Head Machine Screws for mounting assembly to existing rudder holes – Lowes Item #136337 (LINK)
Package of 8-32 x 2 SS machine screws Lowes Item # 136468 (LINK)
Package of 8-32 Stainless Steel Forged Wing Nuts Lowes Item # 136212 (LINK)
Zip Ties, Marine Goop
(Note: Some of the Lowe's links may display "product not available online" but they are regularly stocked in all the local stores)
Cut out a 4” X 1.5” rectangle from the poly cutting board. As pictured, cut an additional slot in the center of the 1.5” side at the ¾” mark that is 2.5” in length as depicted in the photos. Make sure the slit is wide enough to accommodate the width of the aluminum flat stock.
While wearing thick leather work gloves, use a heat gun to bring the poly rectangle up to temperature, focusing on the slotted end. Once the poly rectangle is pliable, secure it in a vice and bend by hand until it looks similar to the one in the pictures. Hold it in the curved position until the poly cools.
Using a vice, make a 90 degree bend in the aluminum stock that will accommodate a proper mounting point for your transducer. Cut the stock to 10” in length above this bend.
Line up the poly rectangle on the stern of the kayak where the preinstalled rudder mounting holes are located. Mark and drill the holes in the poly rectangle and use the ¾” SS Oval head bolts to temporarily mount the unit to the kayak as pictured. Slide the aluminum flat stock arm into the slit in the poly and position the arm so that it is vertical. Note that the aluminum arm will rest against the 2 mounting bolts that hold the poly to the kayak.
Mark and drill a hole starting on one side of the poly cutting board, continuing through the aluminum arm and back out the other side of the cutting board that will accept the 8-32 x 2 SS machine screw. Slide the bolt into position and tighten the wing nut, creating a pivot point for the arm. Clean up the aluminum arm with a grinder making sure to round off all sharp edges.
Remove the factory installed drain plug from the rear portion of the kayak and feed the transducer cable into the hull. Drill a hole through the rubber stopper that is the same size as the transducer cable. Using a razor blade, cut a slit into the stopper until it meets the hole that was just drilled. This will allow the cable to slide into the stopper as pictured. Place a liberal amount of Marine Goop on the stopper, transducer cable and drain hole and slide the stopper snugly into place. Allow it to dry and ensure that you have a watertight and secure seal.
Mount the transducer to the arm and secure the cable with zip ties or similar method. I used some of the hardware that came with my fish finder to route the cable from the rubber stopper to the aluminum arm. That’s pretty much it!- Paul