How to Install a Thru Hull Transducer

Click Here to Watch the HawkEye® Thru-Hull Transducer Video

Hello, my name is Gabe and it’s time for another HawkEye Tech Tutorial! Today I’m going to demonstrate how to install a thru hull transducer.

The thru hull transducer is suitable for outboards, inboard/outboards, single or dual inboard, or jet-drive propulsion. Hull dead rise angle below 20°. Fiberglass or Metal Hull Material. CANNOT be constructed of wood. If you think that this transducer is not suitable for your vessel, contact us and we’ll be happy to review your installation plan and offer suggestions for alternative transducer options.

Let’s begin by unpacking and reviewing the contents of the packaging. In the package there should be a Thru-Hull Transducer with Integrated Temperature Sensor, 30 ft Cable and Connectors, Rubber Gasket, and a Plastic Nut. Water temperature models have a temperature sensor integrated inside the transducer.

If you do not have any of these items please contact and we will rush one out to you!

Tools & supplies required for this installation:

  • Safety goggles
  • Dust mask
  • Powerdrill
  • 1/8” drill bit
  • 2" (51mm),
  • Marine Sealant,
  • Zip-Ties
  • Clean Up Rags and a Mild Cleaning Solvent

If you are going to be storing the vessel in the water you will also need water based antifouling paint and masking tape.

Now, let’s get started.

To obtain the best performance, the transducer should be mounted in a location where the water flow beneath the hull is aeration and turbulence-free. Try to mount the transducer as close to the centerline of the boat as possible. Consult the boat manufacturer for the best transducer placement. If this information is unavailable, follow the guidelines in the installation manual.  

To Get a Good “View” of the Mounting Location, with the vessel out of the water, position yourself at the transom and look at the bottom of the hull towards the bow. Using the illustrations in the manual note anything that could interrupt the clean flow of water to the transducer mounting location.

After selecting the mounting location, place the rubber gasket inside the hull against the mounting location. Ensure that there is at least 1/2” of flat surface area around the rubber gasket. Place a mark in the center of mounting location. Drill a 1/8“ pilot hole on the mark. If there is a rib, strut, or other hull irregularity on the hull bottom near the selected mounting location, drill from the outside. Using a 2“ hole saw, cut a hole from outside the hull. Using sandpaper and mild house hold detergent, sand and clean the area around the hole (inside and outside). Make sure to remove all rough spots and petroleum residue.

Remove the nut and rubber gasket from the sensor. Apply a bead of marine sealant around the lip of the sensor housing. From outside the hull, feed the cable through the hole (plug first) into the mounting hole until all the cable is inside the hull. Insert the sensor into the hole using a twisting motion to squeeze out excess sealant. From inside the hull, align the arrow on the housing towards the bow of the vessel. Slide the rubber gasket onto the housing. Screw the hull nut into place, being sure the arrow on the housing is still positioned forward toward the bow. Remove the excess sealant on the outside of the hull. Finally, route the cable to the display mounting location connect it to the display.

When tightening the nut it is imperative that you hand tighten only. Never use wrenches or pliers to tighten the nut as over tightening can damage the transducer and may lead to sinking. Now that you’ve installed the transducer, allowed sufficient drying time for the sealants, and learned the setup and basic functions of the depth finder, let’s get out on the water and put it to work.