Meet the Garmin GT21-TH Thru Hull Downvu Transducer — the pinnacle of sonar clarity for coastal and offshore anglers. This thru-hull mount transducer delivers the best of both worlds: traditional sonar for deep-water bottom tracking and CHIRP ClearVü scanning sonar for razor-sharp underwater images, so you can see fish arches with superb target separation and precise structure beneath your boat.

• CHIRP ClearVü scanning sonar with a 500 W power rating at 260 kHz (245–275 kHz) and 455 kHz (445–465 kHz) for ultra-detailed underwater visualization and standout target separation.
• Traditional sonar with 600 W power at 50/200 kHz for solid bottom return and effective fish finding in deeper water.
• Stainless steel stem thru-hull design for durable mounting, stable performance, and clean sonar returns across hull deadrises up to 25°.
• Built-in fast-response temperature sensor to track water temperature in real time while you fish.
• Precise beam geometry with Traditional 40°/10° and ClearVü 2.0°×51° at 260 kHz and 1.4°×29° at 455 kHz for both wide-area scanning and narrow, detailed imaging.
• Maximum depth Traditional up to 1,500 ft and ClearVü up to 1,000 ft, helping you locate structure and fish at greater ranges.
• Easy installation designed for hull deadrises up to 25°, with a complete mounting package and installation instructions to guide you step by step.

What’s in the box

• 8-pin transducer with stainless steel stem
• Fairing block
• Isolation plate and bushing
• Mounting hardware
• Installation instructions
• Cable length: 30 ft

Specifications

• Traditional 50/200 kHz; ClearVü CHIRP 260 kHz (245–275 kHz) & 455 kHz (445–465 kHz)
• Traditional 600 W; ClearVü 500 W
• Traditional 40°/10°; ClearVü 2.0°×51° @ 260 kHz and 1.4°×29° @ 455 kHz
• Traditional 1,500 ft; ClearVü 1,000 ft
• Depth and Temperature sensing included
• 8-pin
• 30 ft
• Up to 25° deadrise

Designed for coastal and offshore adventures, the Garmin GT21-TH Thru Hull Downvu Transducer delivers crisp fish arches, clear structure, and dependable readings from the moment you install it. Elevate your sonar capabilities and fish smarter with Garmin’s trusted performance.