Transom installation is generally the simplest way to mount a marine transducer. There are typically only two to four holes used for installation, and the boat can remain in the water the entire time. The alternative to transom transducer installation is in-hull installation, which requires removing the boat from the water and mounting the unit on a flat surface on the bottom of the boat.
Mark the mounting holes on the side of the transom with the least turbulence or water movement. This spot will be determined by the direction of the propeller. Propellers moving clockwise tend to create more water movement on the port side of the boat and vice versa. The transducer must also be installed on the bottom edge of the hull, which will stay submerged in water even when the boat is on plane at high speeds.
Match a drill bit to the diameter of the wood screws in the transducer mounting kit. A slightly smaller drill bit will also work as the holes can be used as pilot holes for the wood screws.
Create 1-inch deep holes, using the appropriate drill bit, where you made the mounting marks. Some mounting brackets require two holes, while others require four. Fill the holes with marine grade sealant.
Line the bracket up with the holes and use the screwdriver to tighten the wood screws. Leave the screws a bit loose so the transducer can be adjusted for better signal.
Loosen the pivot bolt. Most transducers will have a pivot bolt. When that pivot bolt is loosened with the screwdriver and wrench, the angle of the transducer can be adjusted. It is best to use a helper for this step as the boat should be in motion and on plane when the final adjustments are made.
Adjust the transducer. With the boat in motion, adjust the vertical position and angle of the transducer. Refer to the owner's manual for the optimal angle needed for better transducer signal. Before adjusting, don a life jacket as a safety precaution.
- Always fill drilled holes with marine grade sealant to help keep water out of the boat.
- The transducer should be mounted between twin outboard motors.