How to install your fish finder

Nothing contributes more to catching a fish than installing a fish finder. Many boats are pre-rigged with transducer scuppers and battery compartments making installation a breeze.

Kayak-friendly units pack the most advanced features in a small package. On most kayaks, the installation comes down to three simple steps.

Install a fish finder where it won't interfere with paddling or fishing. | Photo: Courtesy Garmin
Install a fish finder where it won’t interfere with paddling or fishing. | Photo: Courtesy Garmin

1. Mounting the display

Fish finder 101:
Side scanning, down scanning, front-view, CHIRP, megahertz and watts, you need to be a rocket scientist to use a fish finder. Not true. The latest generation of fish finders pack a ton of features in small packages. And they’re easy to use.
Down scanning:
Shoots a high-frequency, narrow-beam signal to create a photo-like image of the bottom. Offers incredible detail of structure and vegetation.
Side scanning:
Uses the same signal as down scanning sonar, but shoots to the side to create an image of bottom, structure and fish to the left and right of the kayak. Recently available in forward- and 360-degree scan.
Transducer emits sonar signals on two frequencies to create a detailed image of structure and fish. Provides improved target separation. Best for deep water.

Be sure to mount the fish finder display where it will not interfere with casting, pedaling or paddling. Remember, the cockpit is full of action. Install fish finder out of the way.

Still, the sonar display should be in reach and easy sight. It’s best to install the display close to the transducer and battery.

[ Further reading: Why You Need To Add Side-Imaging Sonar To Your Fishing Kayak ]

Either use the mount supplied by the manufacturer or choose an adjustable arm for additional mounting and display positioning options.

2. Placing the battery

A 12-volt, 10-amp-hour battery is the heaviest gear you’ll carry on the kayak. Keep the battery over the center line and close to the seat.

Prevent the battery from coming in contact with water by elevating it over the bottom of the hull or sealing it in a waterproof battery box. Use heat-sealed, waterproof connectors doused with light oil after each use.

Run the power cable out an existing hatch or drill a small hole in the deck and use a cap available at any marine supply store.

3. Installing the transducer


The transducer can be mounted inside or outside the kayak. Really.

Many fishing kayaks come with a transducer scupper. The sending unit mounts to the bottom of the scupper hole of a sit-on-top kayak and the cable passes through the hole to the display unit. With a little ingenuity, and a transducer mounting kit, the puck is easy to install.

If the boat doesn’t have a special scupper for the transducer, you can glue the transducer inside the hull. The sonar signal will shoot through the plastic. Take a one-inch-thick sheet of closed-cell foam, like a garden mat, and cut a hole slightly larger than the transducer puck. Use silicone sealant to glue the foam to the bottom of the hull. Squeeze a thin layer of sealant into the bottom of the hole, wedge the puck in and fill with more sealant. The transducer will provide a clear picture of the bottom but won’t give an accurate water temperature reading through the hull.

Another option is to use an adjustable transducer arm attached to a gear track to dangle the puck over the side of the kayak. Many models include a base to mount the fish finder display and hold the extra cable. The transducer arm is easy to install and remove, especially helpful if you have one fish finder and more than one kayak.

4. Different types of fish finders

Install a fish finder where it won’t interfere with paddling or fishing. | Photo: Courtesy Garmin


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