Overview

The Garmin 010-11812-20 is a 1 kW pocket mount CHIRP transducer that delivers depth and water temperature for solid fiberglass hull installs. It runs dual-band CHIRP across 42 to 65 kHz (low) and 85 to 135 kHz (medium), so you can cover deeper water and still keep good target separation when fish are tight to structure.

On the low band it is rated to 3,000 ft (914 m), while the medium band is rated to 1,500 ft (457 m). Beamwidth is 25 to 16 degrees on low and 16 to 11 degrees on medium, which helps when you want a tighter look at bottom and bait without giving up the low-frequency reach.

This is a bronze-housing transducer built for a custom pocket or keel-style installation where the face sits flush to the hull. It comes on a 39 ft cable with bare-wire termination, which is common when the transducer is being landed into a compatible sounder module during a new build or refit.

Key features

• 1 kW dual-band CHIRP operation: 42 to 65 kHz (low) and 85 to 135 kHz (medium)
• Depth and fast-response water temperature sensing from one transducer
• Maximum depth ratings: 3,000 ft (low) and 1,500 ft (medium)
• Beamwidth ranges: 25 to 16 degrees (low) and 16 to 11 degrees (medium)
• Bronze housing with a urethane acoustic window for pocket/keel mounting
• Solid fiberglass hull requirement for this pocket-mount style installation
• 39 ft cable with bare-wire leads for hardwiring into compatible sonar/sounder connections

Installation and setup

Pocket mounting is usually done during a build or by a yard that can fabricate a clean recess and fair it properly. The goal is a flush, protected mounting surface that stays in solid water flow and avoids aeration when the boat is on plane.

Because the pocket is custom, the final transducer angle is handled by the pocket geometry rather than a built-in tilt. Take extra care with sealing and bonding at the pocket so the hull remains watertight and the transducer face stays fair to the running surface.

Compatibility and fit

This transducer is intended for Garmin sonar systems that support a 1 kW low/medium CHIRP transducer and accept bare-wire termination. Confirm that your sounder module and chartplotter setup support these frequency ranges before committing to the install, since pocket mounting is not a quick swap like a transom bracket.

It is specified for solid fiberglass only. If your hull is cored or uses a different construction at the intended pocket location, verify that the installation area meets the solid laminate requirement.

Use cases on board

This setup makes sense for boats that spend time offshore, fish deeper structure, or run at speed and still want dependable bottom tracking. It also suits crews that want both deeper-water reach on low CHIRP and tighter target definition on medium CHIRP without changing transducers.

Maintenance and care

Keep the transducer face clean and smooth so growth does not soften returns. When the boat is hauled, inspect the pocket fairing and bedding, and confirm the cable is still well-supported and protected from chafe where it routes into the bilge or rigging channels.