858c & 958c Inside the Hull Transducer Installation

DualBeam PLUS™ Transducer, XNT 9 20 T (858c and 958c only)

NOTE: Do NOT install the Side Imaging® transducer inside the hull, as the side looking beams cannot penetrate the hull. Only the DualBeam PLUS™ transducer can be mounted inside the hull.

If you choose to mount your transducer inside the hull of your boat, perform the procedures in this section. In-hull mounting generally produces good results in single thickness fiberglass-hulled boats. Humminbird® cannot guarantee depth performance when transmitting and receiving through the hull of the boat, since some signal loss occurs. The amount of loss depends on hull construction and thickness, as well as the installation position and process.

This installation requires slow-cure two-part epoxy. Do not use silicone or any other soft adhesive to install the transducer, as this material reduces the sensitivity of the unit. Do not use five-minute epoxy, as it has a tendency to cure before all the air bubbles can be purged, thus reducing signal strength.

NOTE: In-hull mounting requires an installed and operational control head.

NOTE: The integral temperature probe will not work with in-hull mounting, so you may either want to consider purchasing a Temperature/Speed accessory, a Temp. Sensor, or obtaining a different transducer. Humminbird® offers a transducer exchange program to swap the NEW and UNASSEMBLED transducer, accompanied by mounting hardware, for one without an integral temperature probe. Call the Humminbird® Customer Resource Center at 1-800-633-1468for details, or visit humminbird.com for more information.

NOTE: Your transducer may not look exactly like the transducer shown in the illustrations, but it will mount in exactly the same way.

There are several procedures you will have to perform in order to install a transducer inside the hull. They are as follows:

Locate transducer mounting location

Perform a trial installation

Route the transducer cable

Permanently mount the transducer

1.Locating the transducer mounting location

Decide where to install the transducer on the inside of the hull. Consider the following to find the best location:

Observe the outside of the boat hull to find the areas that are mostly free from turbulent water. Avoid ribs, strakes and other protrusions, as these create turbulence.

As a general rule, the faster the boat can travel, the further aft and closer to the centerline of the hull the transducer has to be located in order to remain in contact with the water at high speeds.

Inside the Hull Mount - DualBeam PLUS

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