Overview

The Garmin B164-12-8G is a 1 kW, thru-hull, tilted-element transducer with a Garmin 8-pin connector that delivers depth and water-temperature readings on 50 kHz or 200 kHz. Its fixed 12° element tilt is intended for hull deadrise angles of 8° to 15° at the mounting point, keeping the sonar beam closer to vertical without adding an external fairing block.

This is a low-profile bronze housing that extends less than 6.35 mm (0.25 in) below the hull, which matters on boats that get trailered or sit on bunks and rollers. The 50 kHz element uses a wider 22° x 20° beam and is rated for depth performance to 549 m (1,800 ft), while the 200 kHz element uses a tighter 6° beam and is rated to 244 m (800 ft).

Installation requires access to the inside of the hull and a 95 mm (3-3/4 in) hull cutout, so it is typically planned during a haul-out. The bronze body is intended for fiberglass or wood hulls, where it can be properly bedded, sealed, and bonded as needed for the boat’s corrosion-protection plan.

Key features

• 1 kW traditional sonar with dual-frequency operation at 50/200 kHz
• 12° tilted element for 8° to 15° deadrise angles at the install location
• Low-profile bronze thru-hull housing that protrudes less than 6.35 mm (0.25 in) below the hull
• Beam coverage: 22° x 20° at 50 kHz and 6° at 200 kHz
• Depth and fast-response water-temperature sensing
• Garmin 8-pin connector with 10 m (33 ft) cable
• Requires a 95 mm (3-3/4 in) hull hole for the thru-hull fitting

Installation and setup

Plan the mounting spot where the transducer face will stay in clean, solid water flow at speed, usually close to the keel and forward of prop wash, steps, and strakes. Confirm the deadrise where it will sit; the built-in 12° tilt is meant to match an 8° to 15° deadrise so the element points down instead of off to the side.

Because it is a thru-hull, bedding and torque matter. A clean, flat seating surface and careful sealing around the stem help prevent seepage and keep the transducer aligned, especially on boats that see pounding in chop.

Compatibility and fit

The Garmin 8-pin plug is meant for Garmin sonar equipment that accepts an 8-pin transducer connection. This transducer is a 50/200 kHz conventional unit rated at 1 kW, so it pairs with compatible traditional-sounding sonar systems rather than CHIRP-only transducers.

The bronze housing is intended for fiberglass and wood hulls. For metal hulls, a different housing material and corrosion plan are typically required.

Use cases on board

This is a solid match for anglers and cruisers who want a high-power, conventional 50/200 kHz thru-hull transducer while keeping a low profile under the hull. It also fits boats that get trailered, where minimizing protrusion helps reduce the chance of contact with bunks, rollers, or lift gear.

Maintenance and care

Keep the transducer face free of heavy growth, since fouling can weaken bottom return and temperature response. If you apply antifouling, use a coating labeled safe for transducer faces and avoid building up thick layers that can interfere with sonar performance.