Sjávarbotnsjá GT51M-TH - gegndæla 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 delivers 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 critical for accurate readings.

The choice of location is crucial for optimizing 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 and away from the propeller and propeller shaft.High-performance hulls with chines: Installation must be done in front of the first chine.Long-keel hulls: The transducer should 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 fore-aft axis of your vessel and in an area of clean water, i.e., non-turbulent. Avoid placing it behind frames, stringers, 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 installing the GT51M-TH transducer. This update ensures compatibility and optimal performance between the transducer and your navigation device. You can find the software update instructions in the user manual of your Garmin chartplotter.

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

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

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

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 outside of the hull. Similarly, apply marine sealant to the face of the backing block that will be in contact with the inside of the hull. After tightening all nuts, remove any excess sealant from the outside of the fairing block and hull before it hardens. This ensures smooth water flow over the transducer.

It is crucial to use a flexible, fast-curing marine sealant specifically designed for use below the waterline.