GT56UHD-TH Thru-Hull Sonar - UHD ClearVü/SideVü

Yes, the Garmin GT56UHD-TH transducer is designed to be compatible with Garmin chartplotters. However, it is imperative to update the software of your Garmin chartplotter when installing this transducer to ensure compatibility and optimal performance. Update instructions are usually found in the user manual of your chartplotter on support.garmin.com.

Anti-rotation bolts are crucial for the safety and performance of the GT56UHD-TH depth sounder. They are supplied with the unit and must be installed to prevent the transducer from rotating when the boat is underway. Failure to install them could damage your vessel and compromise the reliability of sonar readings by altering the transducer's orientation.

The choice of location is essential for optimal performance and must be made carefully. Here are the main considerations:

Non-turbulent water: The transducer must be installed in an area where the water is clean, free of air bubbles and turbulence created by strakes, reinforcements, fittings, scuppers, or water discharges.

Distance from engine/propeller:

On outboard and sterndrive boats: in front of and near the engine(s).

On inboard boats: in front of and far from the propeller and the engine shaft.

On single-propulsion boats: do not install in the propeller’s path to avoid cavitation.

On twin-propulsion boats: if possible, between the propulsions.

Specific hull types:

Vee hulls: in front of the first chine.

Full-keel hulls: slightly angled toward the bow, parallel to the centerline.

Fin-keel hulls: 25 to 75 cm in front of the keel and max 10 cm to the side of the centerline.

Displacement hulls: approximately 1/3 of the waterline length from the bow, and 150 to 300 mm to the side of the centerline.

Avoid impacts: Do not install in a location where it could be struck during launching, beaching, or storage.

The transducer must be installed parallel to the bow-stern axis of your vessel.

A fairing block is an accessory that allows you to position the transducer parallel to the waterline, improving the accuracy of sonar data. You must measure the deadrise angle of your boat’s hull at the installation location. If this angle exceeds 5°, using a fairing block is recommended for optimal transducer mounting.

The hole dimensions to drill in the hull vary slightly depending on the hull type:

For the stem hole (central hole for the transducer stem):
Fiberglass hulls (with or without core): 25 mm (1 inch) diameter.
Metal hulls: 32 mm (1 1/4 inch) diameter.
For the anti-rotation bolt holes:
Fiberglass hulls (with or without core): 9 mm (3/8 inch) diameter.
Metal hulls: 13 mm (1/2 inch) diameter.
It is recommended to use the mounting template provided in the product box to mark the hole locations accurately.

The main advantage of a through-hull transducer like the Garmin GT56UHD-TH is its ability to provide optimal and reliable sonar readings. By being installed directly through the hull, it sits in clean, non-turbulent water, which minimizes interference and ensures better clarity and precision in sonar images. This is particularly beneficial for ultra-high-definition scanning functions.

For the installation of the GT56UHD-TH transducer, it is recommended to use a flexible, fast-curing marine sealant specifically designed for below-waterline applications. This type of sealant ensures a strong and durable watertight seal between the transducer (or the fairing block, if used) and the hull of your boat, preventing water intrusion.