Overview

The Garmin 010-10640-20 is a 1 kW bronze thru-hull depth and water-temperature transducer with a fairing block and a Garmin 8-pin connector. It runs traditional 50/200 kHz sonar, giving a wide 19° beam at 50 kHz for coverage and a tighter 6° beam at 200 kHz for target separation.

This style of thru-hull is commonly used when you want consistent bottom tracking in deeper water, with published depth performance up to 2,500 ft (762 m) at 50 kHz and up to 1,000 ft (294 m) at 200 kHz. The housing is bronze and the acoustic window is urethane, and it is intended for fiberglass or wood hull installations.

Key features

• 1 kW traditional sonar for depth and water-temperature sensing
• Dual-frequency operation at 50/200 kHz (19° beam at 50 kHz, 6° beam at 200 kHz)
• Depth performance up to 2,500 ft (762 m) at 50 kHz and up to 1,000 ft (294 m) at 200 kHz
• Thru-hull mounting with fairing block for alignment through hull deadrise up to 20°
• 30 mm (1-3/16") mounting hole size with 121 mm (4.75") usable shaft length
• Garmin 8-pin connection with a 39 ft (12 m) cable
• Fairing block format intended to keep clean water flow across the face at speed (up to 30 knots is commonly cited for this style)

Installation and setup

This is a true thru-hull install, so plan for a 30 mm (1-3/16") hole, inside access for the retaining nut, and enough clearance for the stem length. The fairing block is shaped to match the hull angle and should be oriented so the transducer face sits cleanly in the water flow when the boat is on plane.

Because it penetrates the hull, take the same approach you would for any below-waterline fitting: dry-fit everything, seal with an appropriate marine bedding compound, and torque to spec without stressing the housing. Many owners have a yard or experienced installer handle the final placement so the fairing is cut correctly and the sensor sits in solid water.

Compatibility and fit

The connector is Garmin 8-pin, so it mates with Garmin sounders and chartplotter/sonar systems that accept an 8-pin transducer input. If your Garmin sonar port is the older 6-pin style, an adapter cable is used to bridge between the transducer and the unit.

The bronze housing is intended for fiberglass or wood hulls. If your hull is metal, this is not the right housing type for direct contact installation.

Use on board

This transducer makes sense for boats that run a conventional 1 kW sounder channel and spend time offshore, over wrecks and reefs, or in deeper coastal water where a 50 kHz element helps hold bottom. It is also a common pick on boats around 30 ft and up where there is room for a fairing block and a solid thru-hull location away from strakes, steps, and aerated water.

Maintenance and care

Keep the transducer face clean for consistent readings, especially if the boat lives in the water. If you apply bottom coatings, use products intended for transducers so you do not dull sensitivity, and avoid heavy paint build-up on the acoustic window.