Boat Rigging Part 6: Transducer Rigging

Installing the primary transducer correctly is key to producing the right kind of information through the head unit. Research, measure three times and proceed.

Installing a transducer is a simple, yet extremely important task. If we don’t put the transducer in the proper place it can easily get ripped off of the boat, or not provide the unit with the best information.

While my boat is fiberglass and has a lot of mounting options you still want to get it right the first time and avoid drilling unnecessary holes in your hull. If you have an aluminum boat I would highly recommend a transducer board that can be glued and/or screwed to the transom. This ensures that no additional holes are drilled into the hull, regardless of how many times you need to move or replace a transducer.

Once the mounting area has been determined and is free from obstructions on both the boat and trailer. It’s also worth noting: It’s important that the location will provide the best amount of “clean” or bubble-free water. In short, make sure that the transducer sits just below the bottom of the hull.

The best way to check this is to use a straight edge against the bottom of the hull. I have found it best to use the split point of the transducer—where the two pieces of the shell come together—as the point that I want to level with the bottom of the boat.

The humminbird transducer has two slots that allow for travel and slight adjustment if you don’t get it exactly right. Drill the holes in the middle of this track so that you have room for error in both directions.

Next, use a countersink bit to remove a little bit of glass so that no spider cracking can occur down the road. Do this for all other holes that are drilled in this project.

Go ahead and dry fit the mount again to make sure you have it aligned properly, and then mark the hull where the transducer mount needs to lineup. Remove the transducer and fill the holes with marine-grade silicone.

After replacing the transducer, use the straight edge to line it up correctly and use a screwdriver to tighten both screws down. Humminbird has an extra hole that prevents the bracket from kicking up and protecting the transducer if you were to hit something. This will, however, keep you from being able to make those small adjustments in the slotted groves. This should not be added until you have spent a few days on the water and are confident it is in the ideal position.

Snake up the cord along the hull and drive it through an existing rigging hole if possible. I prefer to use small plastic clamshells to secure the wire. Again, be sure to countersink the drilled hole and fill it with silicone before permanently securing.

Finally, run the transducer wire to the head unit. Brackets will differ from company to company, but the concept and procedures are nearly the same. It is also wise to check with a dealer or look at the boat model to see where others have placed their units.

Research is key before digging into this as you don’t want to drill too many holes in your boat! Online forums can be a great place to get photos of both good and bad mounting locations before you start drilling.

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Capt. Ross Robertson

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