How to Mount a Depth Finder on an Aluminum Boat

Advanced depth finder (recording fathometer) and sonar unit

Mounting a depth finder is about finding the right place inside your boat to mount the transducer--the sensor head that turns the hull of your boat into a receiver for the signals the depth finder bounces off the bottom. Once you've located that one perfect place and mounted the transducer, set up the display unit and connect the cable between the transducer and the display unit on your console or on your dashboard.

Difficulty:

Moderately Challenging

Instructions

Things You'll Need

• Depth finder
• Boat
• Marine epoxy
• Waterproof paint stick
• Mild soap and fresh water

1. Use the 3-pin press-and-screw connector on the coaxial cable that came with the depth finder to connect the depth finder and the transducer. The transducer is the "send and receive" part of the unit. The best place to mount the transducer is along the center line of the boat, near the back.

2. Go boating with a friend. Make sure that there's just enough water in the bottom of the boat to cover the transducer. While you run the boat at low speed, have your friend move the transducer around inside on the bottom of the boat, until you get good, clear depth readings. Speed up and see if the readings scramble. If they do, keep moving the transducer until you get good readings at high and low speeds.

3. When you get good readings, have your friend mark the location with a waterproof paint stick. This is the "sweet spot" to mount your transducer. Disconnect the transducer from the depth finder by unscrewing the coaxial cable connector from the transducer.

4. Clean up the sweet spot with a little soap and water and dry it completely, since dirt, oil and grease will cause you to get false readings. Mix up the two-part epoxy adhesive and apply a thick layer of glue to the sweet spot, at least as big around as the transducer.

5. Push the transducer down into the epoxy, twisting it as you push to remove any air bubbles. Don't push it so far down that it pushes all the epoxy out from under it. Let the epoxy cure for at least a day before you launch the boat again.

6. Mount the depth finder display near your boat's control station according to the manufacturer's instructions so that it can be seen while you are operating the boat. Connect the 3-pin press-and-screw connector from the depth finder to the transducer.

Tips & Warnings

• Your depth finder uses the hull of the boat as a receiver for the signals returning from the lake or river bottom.

• When working with epoxy adhesives, follow the cautions on the product label. Wear your life jacket as required when operating your vessel.

References

• Installing an Inside the Hull Transducer

Resources

• About Fathometers