GARMIN GT21-TM Plastic Transom M DownVü Transducer
The GARMIN GT21-TM is a plastic transom mount transducer designed for DownVü scanning at 500 W (CHIRP 260/455 kHz) and traditional sonar at 600 W (50/200 kHz). It connects via an 8-pin connector, facilitating installation on sportfishing and recreational vessels for enhanced underwater imaging.
Compatibility & Applications
- Pairs with GARMIN chartplotters for enhanced sonar imaging.
- Mounts on the transom of vessels for optimal underwater viewing.
- Fits various boat sizes, including 20–30 ft vessels.
- Integrates with NMEA 2000 networks for system-wide connectivity.
- Replaces older GARMIN transducers with 8-pin connectors.
- Mounts on both sportfishing and recreational boats to improve navigation.
- Wires to existing sonar systems for immediate functionality.
The transducer provides detailed underwater imagery, crucial for fishing and navigation. It is specifically installed on the transoms of sportfishing boats, and its IPX7 rating ensures protection against water ingress, distinguishing it from generic models that lack such robust environmental protection.







