How To Mount A Transducer On An Aluminum Boat

"This site contains affiliate links to products. We may receive a commission for purchases made through these links."

All the while you were wondering how to put the transducer on an aluminum boat and you thought it was a complicated thing, rocket science. 

Now, in just a few steps, you can prove that it’s not difficult. If you just have a bit of love and affection for fishing then you’re ready to go sailing and catch the biggest trophy of your life.

What we need to know before we mount a transducer

There are many ways to install the transducer. There are also many ways to install a transducer on the forage or stern mirror. 

A stern installation is not recommended for all ship skips even though, they have a stern mirror and an outboard engine. 

These are thought of as “stepped-type” shells, commonly found in the United States.

The biggest problem with any transducer mount is the air bubble that creates any shell of a ship that passes through the water, only the difference is where it’s happening.

For stern installation, this is also the biggest problem, because it is possible to make the error and install the probe in the “bubble zone”.

However, a very steady installation, if well-affected, can give the best “high-speed” results.

It is necessary to know that for ships with one outboard engine on the stern, at least the bubbles are formed in the keel zone, and in that sense, this position on the stern mirror would be optimal (it means in the middle).

 But in such a way of installation, there is a problem with the cavitation of the propeller.

Therefore the transducer is moving towards the side. Usually, an optimal place is about 20-40 cm from the keel and mostly to the right (it does not always have to be). 

When determining the right spot, it can get a clear reflection and the first great speed of the ship.

Recommendations for the best position for installing a transducer

  • Mount transducer as close to the center of the boat.
  • Do not mount the plug behind the ribs, screws, plugs, inlet or outlet holes, or anything that could produce bubbles and cause water turbulence.
  • To achieve optimum performance, a transducer must be mounted in a clean water stream (non-turbulent).
  • Do not install or mount a transducer in locations where it may be damaged when entering the boat, water draining, or storage.
  • Do not mount on single-screw bolts in the bolt path. A transducer can cause cavities that can reduce the boat’s performance and damage the bolt.
  • On two-bladed boats, if possible, fill the cavity between the screw thread.

Installing the mounting accessories on the back of a boat

If you mount a transducer on aluminum using screws, it is recommended to use the drill bit extension to extend the upper part of the hub to thread the bolt head up to the upper layer of the gel coat. 

This prevents cracks in the gel coat layer when tightening the screws.

Follow these steps:

1. Place a transducer holder so that the center of the bottom of a transducer is aligned with the bottom edge of the transom mirror and parallel to the surface of the water.

2. Place a transducer so that it is parallel to the water surface and mark the centers for the two outer openings and the center hole on a transducer holder.

3. About a 4mm (5/32 inch) drill, wrap a self-adhesive tape at 15 mm (19/32 in.) From the tip of the drill to avoid over-drilling.

4. If mounting a transducer on an aluminum boat, we must place a self-adhesive tape above the drill hole location to reduce cracks in the gel coat layer.

5. Using a 4 mm (5/32 inch) drill on marked locations.

6. Attach the sealant to the supplied 20 mm bolts and attach a transducer assembly to the stern mirror.

Tip: The third screw in the lower central opening stabilizes the bracket.

7. If you need to route the cable through the stern mirror, select and mark the area at a safe distance from the water surface.

8. Fit a transducer cable tie approximately in the first third of the distance between a transducer and the tip of the transom or the aperture.

9. Mark the transducer hole location for the cable tie and a 3.2 mm (1/8 inch) drill the hole deep about10 mm (3/8 inch).

10. Attach the seal of the boat to the attached 12 mm bolts and fasten the cable tie to the stern mirror.

11. Repeat steps 10 to 12 to set the other cable tie to two-thirds of the distance between the probe and the tip of the transom or the probing hole.

12. If you have marked a test hole in step 9, use a 25 mm (1 inch) drill to punch the opening through the stern mirror.

13. Run a transducer in the water to make sure it is all well-positioned.

  • If you pass the cable through the opening, pass it through the hole and insert the cable entry cover.
  • If you do not run the cable through the opening, place it over the top of the neck.

Avoid installing cables with electrical wires or other sources of electrical interference.

Mounting of the cable entry cover

If you have carried the cable through the stern mirror after installing the probe, you must install the cable cover to prevent water penetration into the vessel.

  • Insert the cable cover above the opening and the cable so that the aperture is pointing downwards, then mark the location of the two probes.
  • Remove the cable feed cover and use a 3.2 mm drill bit to drill approximately 15 mm deep probes (19/32 in.).(1/8 in.) Drill the probes deep about 10 mm (3/8 in).
  • Apply the cable gasket in the cable gland so that it completely covers the cable and that there is an additional layer of the gasket around the opening and the cable.
  • Place the cable cover over the opening and the cable so that the opening is facing downwards.
  • Apply the seal of the boat to the attached 12 mm M4 bolts and then attach the cable cover to the stern mirror.
  • Wipe the excess seals for the boat.

Installation check

Before you leave the boat in the water for a long time, you need to check for leaks.

Since water is required for the transmission of the sonar signal, the probe must function properly in the water. 

You cannot get depth or distance reading out of the water. After placing the boat in the water, check for leaks around the screw holes that are added beneath the water surface.

Check the mounting of a transducer

Set the depth of a transducer in small steps. Positioning a transducer too far can significantly affect the performance of the boat and expose the danger of being hit by underwater objects.

Inspect the mounting of a transducer on the open end of the cruise control without any obstacles. When testing a transducer, pay attention to your environment.

  • When the boat is in the water, turn on the Chartplotter.
  • Boat run at low speed. If the Chartplotter looks right, gradually increase the navigation speed while simultaneously tracking the Chartplotter.
  • If you miss the signal start all again from the beginning.
  • Return the boat speed at which you missed the signal and moderately turn the boat in both directions while simultaneously tracking the Chartplotter.
  • If the signal strength increases during the turnaround, adjust the pulse to expose another 3 mm (1/8 inch) underneath the cruise liner.
  • Repeat steps 2 – 4 to remove the pad.
  • If the signal does not improve, move the transmitter to the second position on the mirror and repeat the check.


It’s essentially nothing complicated if you follow the steps. You need to drill a couple of holes where you will install the transducer.

What is most important is to make sure that everything is sealed properly so that there is no space where the water could drain and make a problem with the signal when using the transducer in the water.

Since aluminum is a very lightweight, easy-to-drill material, be sure to mark the holes very well and drill them sufficiently wide enough that the screws themselves can hardly pass through the holes. 

This ensures that the hole is filled.

With the right aluminum-compatible transducer and a couple of household tools, you’ll be able to equip your boat with the ability to transmit information from the ocean or lake with ease.

Recent Posts