GT56UHD-TM Sonar - UHD ClearVü/SideVü Transom-Mount Transducer

The Garmin GT56UHD-TM is a transom-mount transducer. This means it is installed on the outside of the boat's transom using a bracket and screws, providing a non-invasive installation compared to through-hull models.

The GT56UHD-TM is designed to integrate with compatible Garmin navigation units equipped with the appropriate connectors. A software update of the chartplotter is usually required to ensure compatibility and optimal performance.

Yes, the GT56UHD-TM transducer is compatible with all hull materials. It is designed to be mounted on the transom and requires constant contact with water to function correctly.

For best results, the GT56UHD-TM transducer operates optimally at speeds below 34 mph (approximately 55 km/h) and in waters with minimal turbulence. Higher speeds may degrade sonar signal quality.

Installing the GT56UHD-TM transducer on the transom involves several steps:

Select an optimal location, away from the propeller and turbulence sources.Mark the mounting hole locations using the provided template.Drill 4 mm (5/32 in) pilot holes to a depth of approximately 18 mm (7/10 in).Apply marine sealant to the screws and secure the transducer assembly to the transom.Run the cable and attach the cable clamp.Install the cable entry cover if the cable passes through the transom.It is critical to consult the full installation instructions for precise details.

The transducer is supplied with a standard cable. If the cable is not long enough to reach your chartplotter, you can add a Garmin extension cable (references 010-11617-42 or 010-11617-32). However, to avoid signal degradation, it is recommended not to extend the cable beyond 9 metres (30 feet).

The transducer must be mounted at least 38 cm (15 inches) from the propeller. Additionally, it is recommended to place it on the side opposite the prop wash (the current created by the propeller) to minimize interference. If the propeller rotates clockwise, mount the transducer on the starboard side (right when facing forward); if it rotates counterclockwise, mount it on the port side (left).

To minimize interference, it is recommended to:

Mount the transducer away from the propeller and any source of turbulence (chine, strakes, ribs, etc.).Keep the transducer cable away from ignition wires, batteries, electric motors, and high-energy cables (radar, audio amplifier, autopilot pump).Ensure proper grounding of the sonar unit and other equipment.If the transducer cable must cross a power cable, route them at 90 degrees to each other.Avoid mounting the transducer behind through-hull fittings, water intake or discharge openings, or hull irregularities.If using multiple transducers, mount them at least 60 cm (24 inches) apart.

If your boat spends a significant period in the water, it is recommended to cover the transducer and mounting hardware with water-based antifouling paint. This helps prevent marine growth that could affect performance. Do not use acetone or acetone-based products, as they damage the transducer's plastic housing.

No, the GT56UHD-TM transducer is not recommended for stepped hull boats due to the turbulence generated by the hull’s chines. It is also not recommended for sailboats because the excessive heel could compromise the transducer’s constant contact with the water.

It is imperative not to cut the transducer cable. Cutting the cable will void the warranty of your product.

The transducer must be mounted parallel to your boat's waterline. Incorrect orientation can degrade sonar performance, as the beam would not be perpendicular to the water surface.

The transducer must extend 3.5 mm (0.125 in) below a fiberglass hull or 10 mm (0.375 in) below an aluminum hull to ensure optimal water contact without turbulence.

To install the GT56UHD-TM transducer on the transom, you will need the following tools:

Phillips screwdriver size #2DrillBits: 4 mm (5/32 in), 3.2 mm (1/8 in), 25 mm (1 in)Masking tapeMarine sealantSafety goggles, hearing protection, and a dust mask are also recommended.

Yes, the Garmin GT56UHD-TM transducer is equipped with an integrated water temperature sensor, allowing you to view this data directly on your compatible chartplotter.

After installation, it is important to test the transducer in open water, without obstacles. Here are the steps:

Launch the boat and check for leaks around the screw holes below the waterline.Turn on the chartplotter.Drive the boat at low speed, then gradually increase speed while observing the chartplotter.If the sonar signal is lost or significantly degraded at a certain speed, note this speed.Return to this speed and perform moderate turns in both directions. If the signal strength improves while turning, this may indicate a need to adjust the location or angle of the transducer.Small incremental adjustments may be required to optimize performance.

Yes, transom-mount transducers like the GT56UHD-TM are suitable for towed boats, especially when used with a folding bracket (not included and compatibility must be verified). However, they are vulnerable to external damage from trailers or underwater obstacles, so precautions are necessary.

Although the GT56UHD-TM transducer has an integrated splash guard, if you notice excessive water ejection, it is recommended to recheck mounting considerations and adjust the transducer position if necessary. A slight adjustment of the angle or depth often resolves this issue.

Yes, the GT56UHD-TM transducer can be installed on an electric trolling motor. The installation involves securing the transducer bracket to the motor body using hose clamps. Ensure the cable is routed to avoid pinching or excessive bending and does not lie in the path of the trolling motor propeller.

The Garmin GT56UHD-TM transducer is a high-definition transducer that provides advanced sonar capabilities, including:

Traditional CHIRP sonar for clear fish detection and precise details.ClearVü UHD sonar for near-photographic images of what lies beneath your boat.SideVü UHD sonar for detailed views of structures and fish to the sides of your boat.These combined technologies provide a complete and detailed view of the underwater environment.