How to mount a sonar fish finder on a kayak: a simple and easy way

Savvy fishermen / fisherwomen often use sonar fish finders to help them locate fish, structure (e.g., humps, drop offs, ledges, shoals, and dips). DIYers have come up with innovative ways to mount sonar transducer and fish finder itself. For example, some may use a suction plate to mount the transducer while others enjoy using PVC pipes for supporting the transducer and also the fish finder.

Read my post: how to use fish finders to help you catch more fish

Here, I am going to talk about a different method of mounting sonar transducers onto kayaks.

Materials you’ll need:
(1) 1/4 inch by 1 1/4 inch flat head stove bolts and nuts.
(2) brass washers with sunken design, which can provide an increased bearing surface (to reduce stress at the holes you’ll drill on the kayak).
(3) a drill or a Swiss army multi-tool knife.
(4) a slotted flat steel bar (1-3/8 in. x 36 in. Zinc Steel Punched Flat Bar with 1/16 in. Thick from The Home Depot).
(5) a saw for cutting the slotted flat steel bar.

(1) at one end of your slotted metal bar, cut off the excessive metal bar so that the edge near the first slot will not touch the top of the transducer and prevent you from mounting the transducer onto the first slot of the metal bar.

(2) secure the transducer onto the first slot of the metal bar using a bolt, nut, and washer, as shown in the picture below.

Mounting a sonar transducer
Close-up of sonar transducer mounted on a slotted metal bar

(3) shape the other end of the slotted metal bar so that the slots on the metal bar will touch the surface of the top of the cockpit area of the kayak.

Tips: You may want to secure the transducer near your cockpit so that it’s easily accessible for mounting and dismantling. Typically, sonar transducers work best when you place it slightly (say, 2 inches or 5 cm) below the bottom of your vessel. So, you may want to take a measurement and mark where you want to bend the slotted metal bar.

Sonar transducer mounted on a slotted metal bar
Sonar transducer mounted on a slotted metal bar. The metal bar has been bent to follow the shape of the kayak.

(4) after you have the slotted metal bar bent nicely, fit the metal bar on the kayak nicely and choose two slots and drill holes on the kayak for the two chosen slots, through which two bolts will be installed.

(5) put a washer on the flat-head end of a bolt, slide the bolt through one of the two holes on the kayak from bottom to top. Put a second washer and then a nut on the bolt. Tighten the nut. Do the same thing for the second hole you drilled. Now you have installed on the kayak two bolts (with 4 washers and 2 nuts in total) with room for a metal bar and one more nut on each bolt. Each hole on the kayak will be in-between the two washers shown in the picture below.

Bolt, nut, and washer
The way you use bolt, nut, and washer for securing the slotted metal bar and the transducer of sonar fish finder onto your kayak
Mounting fish finder transducer
Bolts on a kayak for mounting fish finder transducer

(6) now you can fit the slotted metal bar onto the two bolts you just installed on the kayak. Put nuts on top of the slotted metal bar and tighten them. I usually won’t mount the metal bar and transducer until I am on more than 30 inches (75 cm) of water so that the transducer won’t touch the lake bottom.

Sonar fish finder transducer mounted on a kayak
Sonar fish finder transducer mounted on a kayak
Kayak Fishing
Kayak Fishing on Pigeon Lake, Alberta May 2015. A sonar fish finder was mounted on the bow using the bungee cords.

Thank you for reading. Happy kayaking and fishing!

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