Sonda GT51M-TH - transversal CHIRP/ClearVü/SideVü

The Garmin GT51M-TH transducer is a thru-hull transducer designed for permanent and robust installation through the hull of your vessel. It provides consistent sonar performance without interference, unlike transom-mounted transducers which can be affected by turbulence. Its thru-hull installation ensures better signal quality by avoiding air bubbles and disturbances, which is essential for accurate readings.

The choice of location is crucial to optimize the performance of the GT51M-TH transducer. Here are the guidelines:

Outboard and sterndrive vessels: Mount the transducer in front of and close to the engine(s).Inboard vessels: Mount it in front of and away from the propeller and propeller shaft.Redans hulls: The installation must be done in front of the first redan.Long keel hulls: The transducer must be mounted slightly angled toward the bow, parallel to the centerline.Fine keel hulls: Position it between 25 cm and 75 cm (10 to 30 in.) in front of the keel and no more than 10 cm (4 in.) from the centerline.Displacement hulls: Install it about one-third of the waterline length from the bow, and between 150 mm and 300 mm (6 to 12 in.) to the side of the centerline.In all cases, the transducer must be mounted parallel to the bow-to-stern axis of your vessel and in an area of clean water, i.e., non-turbulent. Avoid placing it behind strakes, frames, fittings, water intake or discharge openings, or anything that could create air bubbles or turbulence. It must also not be in the path of the propeller.

Using a fairing block is recommended if the deadrise angle of your hull at the mounting location exceeds 5°. The fairing block allows the transducer to be positioned parallel to the waterline, which significantly improves the accuracy of sonar readings. To determine whether a fairing block is necessary, you must measure the deadrise angle at the exact installation point. The block can be cut to match your hull's deadrise angle, with a maximum cut angle of 25°.

Yes, it is mandatory to update the software of your Garmin chartplotter when you install the GT51M-TH transducer. This update ensures compatibility and optimal performance between the transducer and your navigation device. You can find the instructions for the software update in the user manual of your Garmin chartplotter.

The Garmin GT51M-TH transducer is designed to be installed on various types of hulls, including:

Fiberglass hulls (with or without core).Metal hulls.However, the installation process and specific tools may vary depending on the material and structure of your hull. Detailed instructions are provided for preparing each type of hull (fiberglass with core, without core, and metal) to ensure proper and secure installation. It is important to consult the installation manual for specifics related to your hull type.

To ensure a watertight seal and prevent water ingress after installing the GT51M-TH transducer, you must apply marine sealant correctly. Key steps:

Apply marine sealant around the base of the transducer shaft and the anti-rotation bolts before inserting them into the hull. If you are using a fairing block, also apply marine sealant to the face of the block that will be in contact with the hull exterior. Similarly, apply marine sealant to the face of the backing block that will be in contact with the hull interior.

After tightening all nuts, remove any excess sealant from the exterior of the fairing block and hull before it cures. This ensures smooth water flow over the transducer.

It is critical to use a flexible, fast-curing marine sealant specifically designed for underwater use.

Follow the manufacturer’s installation guidelines for torque specifications and sealant application thickness.