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How to Mount a Transducer on an Aluminum Boat in Only 3 Steps

Written by Anthony Roberts / Fact checked by Jonathan Larson

How to Mount a Transducer on an Aluminum Boat

Answering the question, ‘How to mount a transducer on an aluminum boat?’ would help you save some time and money on the process. Know and understand the necessary steps so you can do it yourself.

On an aluminum boat, a hull transducer can be attached easily to a single mounting hole. Another option is using the transom bracket to connect the transducer to the lid or the tube.

This article will be your guide in executing the second option as most owners of aluminum boats prefer it due to the firm and secure attachment or mounting. First-timers will surely learn a lot, as every key detail is in this guide.

Know More About Transducers

A boat’s transducer is referred to as an ultrasonic transmitter and a receiver at the same time. It paves the way to translate the sound pulse into depth, structure, and more. When installed for fishing, it’s sensitive enough to give a signal to a fish finder.

It can also convert electrical pulses into acoustic energy or sound waves and vice versa. When used for fishing, a boater should closely look at the fish anatomy to know how it works with the fish finder.

Every fish has an air bladder filled with gas. This substance has a different density compared to the physical aspect (flesh and bone) of a fish and even the surrounding water. The air in the bladder significantly changes the fish buoyancy.

The increase and decrease of density reach the echo sounder. Then, markedly bounces off the fish. The echo notifies the transducer, sending it back to the echo sounder. Due to the differences, it will appear as a fish or a terrain.

Why do boaters install transducers on their aluminum boats? Aside from fishing purposes, a transducer lets them see movements and any structure underwater and determine water depth. It’s worth mounting, right?

Preparations Before Mounting a Transducer on an Aluminum Boat


Monitor Placement

Like with any electronic device, you have to choose the size and the placement of the screen. You would likely put it inside the gunnels where you can easily see it from the driving area. It may be damaged or knocked when placing it outside.

It’s also important to isolate the transducer because an aluminum boat can transfer unnecessary noise. It’s recommended to place it in a case made of gasket material and something rubbery to lessen vibration that sometimes creates sounds.

When a transducer is mounted on a transom, it’s trouble-free to secure and firmly attach. It’s because this area is free of any disruption. Furthermore, water flows smoothly on the transducer’s face.

What you need to foresee is that the water flow washes over the transducer while you’re underway. Also, be aware that there are some rivets somewhere on the transom.

Due to the rivets, you have to arrange the stakes or ribs so that it does not get in the way of the transducer. You also have to check if the connector plug on the cable is compatible with the transducer port with the chosen fish finder.

Alignment of Transducer

Alignment is crucial when installing a transducer on an aluminum boat. Aluminum is lighter than fiberglass. Thus, it’s advisable to make it lean by a few degrees when the vessel is on the waters.

Allowing it to lean will make a difference in the transducer’s performance, especially with the side imaging type. Experts talk about the scum line which is the waterline that’s across the transom.

The water line surfaces because of the boat’s load and the characteristics of the ride. Once the transducer is on the waterline’s level, the aluminum boat will achieve its performance expectations.

Steps for Mounting a Transducer on an Aluminum Boat


Most boaters would likely mount the transducer on a transom since it’s unnecessary to have large holes on the boat’s bottom part. Also, you don’t have to worry about how to discard the interference of trailer bunks.

However, there’s one thing you have to be concerned about when installing the transducer on the transom. Excessive aeration may occur as water streams under the hull and agitates the water flow.

Just follow these steps so you can avoid possible troubles. But first, collect these materials:

  • Transom-mount transducer
  • Power drill (drill bit set and countersink)
  • Marine sealant
  • Electric cable
  • Masking tape or cable clamp
  • Mounting bracket

Step 1: Positioning the Mounting Angle

As a rule of thumb, the transducer should be on the starboard side because it’s the part that has the fewest turbulence. Thus, you give the transducer a chance to perform well.

The standard mounting angle on the transom is 18 degrees. It may vary as transom mount kits have shims. Just make sure that it is angled bow high at 3 degrees. It simply means that the primary edge of the transducer is slightly tilted up.

Nose-down mounting can cause turbulence and awful performance. You may add the shims if necessary to proceed to mounting.

Step 2: Brackets to Mount the Transducer

Be open to adjustments when mounting the bracket, especially the possibility of lowering the transducer into the water. The primary edge of the transducer should be under the transom with a gap of 1/8 inch.

Keep an eye on the holes towards the bottom of the bracket by marking them. You have to specifically do it on the bracket’s adjustment openings. Doing so will allow you to move the bracket up and down.

Setting the bracket this way will help you in case there will be poor readings. When you get speedy, you can lower the transducer to improve the gathering of data.

After marking the holes, you can start drilling. There’s an arrow on the bracket that aligns with the transom’s bottom part. You have to use the marine sealant on every mounting hole. The next step will be tightening the screws.

Step 3: Adding the Transducer to the Bracket

Insert the pivot posts of the transducer on the top of the bracket. Click the posts in place by pushing them down. Rotate it downwards to make it snap into the brackets. Then, run the cable and connect it to the fish finder.

You have to use sealant and a cable cap for the cables to protect them from water. A cable clamp or masking tape to secure their length may be needed.

Make the Transducer Work!

The goal of learning how to mount a transducer on an aluminum boat is to gather data under the water. It’s necessary to follow this article so you’ll have the skills to optimize the transducer’s performance.

Thus, you can make use of it when you go fishing. With the right way of mounting, adjustments can be done once the transducer acts up. Needless to say, poor readings can’t be avoided when underway.

Read more: Reinforced aluminum boat.

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