Garmin GT20-TM Transom Mount Transducer – 4-Pin Connector is designed for anglers who need traditional sonar and CHIRP ClearVü scanning sonar from one compact marine transducer. Suitable for shallow-water fishing, it helps compatible Garmin fish finders display traditional fish arches together with clear views of fish, underwater objects, and bottom structure passing beneath the boat. This combination gives anglers useful information for locating fish, studying changes in depth, and understanding the underwater environment.

The GT20-TM operates at traditional sonar frequencies of 77/200 kHz and supports ClearVü CHIRP frequency ranges of 435–475 kHz and 800–840 kHz. Traditional sonar provides familiar fish-arch returns, while ClearVü scanning sonar produces a more detailed view of structure and targets below the hull. Its traditional sonar beamwidth is 45°/15°. ClearVü beamwidth is 2.5° × 53° at 455 kHz and 1.6° × 29° at 800 kHz, allowing the transducer to collect different levels of underwater detail and coverage.

This Garmin transducer has a power rating of 500 W for both traditional and ClearVü sonar. Its specified maximum depth is 1,900 ft for traditional sonar and 750 ft for ClearVü, although actual depth performance can vary according to water conditions, bottom composition, and the connected sonar display. A built-in fast-response temperature sensor supplies depth and water-temperature information to a supported Garmin marine display. The unit does not provide speed data.

A 20 ft cable gives installers practical routing length between the mounting position and the compatible display. The integrated 4-pin connector identifies this version as a Garmin 4-pin transducer, so buyers should check the transducer port and compatibility information for their Garmin fish finder or chartplotter before ordering. Connector type alone should not be used as the only compatibility check.

The unit can be installed as a transom mount transducer or fitted to a trolling motor using the included mounting hardware. Its support for transom angles from 0° to 70° provides flexibility across different boat installations. Correct positioning is important because a properly installed transducer should remain in clean water flow and be aligned according to Garmin’s installation instructions. The package includes both transom and trolling-motor mounts, together with installation instructions.

For fishing boats and other small recreational vessels operating in shallow and inland waters, the GT20-TM provides a practical way to add depth, temperature, traditional sonar, and ClearVü imaging through one fish finder transducer. Its dual mounting options also make it useful for permanent transom installations or suitable trolling-motor arrangements. Buyers looking for a boat transducer should confirm that their display supports the GT20-TM’s sonar frequencies, functions, and 4-pin connection before installation.

Key Features:

• The Garmin GT20-TM Transom Mount Transducer – 4-Pin Connector combines traditional fish-finding sonar with CHIRP ClearVü scanning sonar for viewing fish, underwater objects, and bottom structure.
• Traditional sonar operates at 77/200 kHz and displays recognisable fish arches on a compatible Garmin sonar unit.
• ClearVü CHIRP supports 455 kHz and 800 kHz bands, covering frequency ranges of 435–475 kHz and 800–840 kHz.
• The transducer provides 500 W of power for traditional sonar and 500 W for ClearVü scanning sonar.
• Maximum specified depth is 1,900 ft with traditional sonar and 750 ft with ClearVü, subject to operating and water conditions.
• Traditional sonar beamwidth is 45°/15°, while ClearVü beamwidth is 2.5° × 53° at 455 kHz and 1.6° × 29° at 800 kHz.
• A built-in fast-response temperature sensor provides water-temperature information alongside depth readings.
• The integrated 20 ft cable offers useful routing length between the transducer and a compatible fish finder or marine display.
• The 4-pin connection is intended for compatible Garmin marine electronics; display compatibility should be confirmed before purchase.
• Supplied mounting options support installation on a boat transom or a suitable trolling motor.
• The transducer supports transom angles from 0° to 70° when installed according to the supplied instructions.
• The package includes the transducer, transom mount, trolling-motor mount, and installation instructions.

Applications / Suitable For:

• The Garmin GT20-TM Transom Mount Transducer – 4-Pin Connector is suitable for shallow-water anglers who want both traditional sonar and CHIRP ClearVü underwater imaging.
• Suitable for fishing boats equipped with a compatible Garmin fish finder, sonar display, or chartplotter with the required 4-pin transducer connection.
• Useful for locating fish and viewing bottom contours, submerged objects, and underwater structure beneath the boat.
• Suitable for monitoring water depth and temperature during fishing and general small-boat operation.
• Designed for transom-mounted installations where the transducer can maintain suitable contact with clean water flow.
• Can also be installed on a compatible trolling motor using the included trolling-motor mounting hardware.
• Appropriate for freshwater and other fishing environments where traditional sonar and detailed downward scanning views are required.

FAQs:

Q: What does the Garmin GT20-TM Transom Mount Transducer – 4-Pin Connector display?
A: When connected to a compatible Garmin display, it provides traditional fish arches, CHIRP ClearVü images of objects and bottom structure, depth readings, and water-temperature information.

Q: Does the Garmin GT20-TM support both traditional sonar and CHIRP ClearVü?
A: Yes. It supports traditional 77/200 kHz sonar and ClearVü CHIRP frequency ranges of 435–475 kHz and 800–840 kHz.

Q: Can this Garmin GT20 transducer be mounted on a trolling motor?
A: Yes. It includes hardware for transom mounting and trolling-motor mounting. Installation should follow Garmin’s supplied instructions.

Q: Will this 4-pin transducer work with every Garmin fish finder?
A: Compatibility is not universal. Confirm that the Garmin display supports the GT20-TM, its sonar functions, and its 4-pin connector before ordering.