Garmin Ultrasonic Speed Sensor

Designed for use with all types and sizes of sailboats and powerboats, Airmar's revolutionary CS4500 makes cutting-edge speed sensing affordable. Instead of a paddlewheel, it uses two transducers mounted in one compact housing to detect particles in the water and calculates speed based on their distance apart. The CS4500 reacts instantaneously to changes in boat speed and is one of the most reliable and accurate speed sensors on the market.

With no moving parts, the ultrasonic sensor is capable of speed reading accuracy as low as 0.1 knots (0.1 MPH). By eliminating the traditional paddlewheel, there is no fouling, and drag is reduced to a minimum. Unlike paddlewheels, the CS4500 is engineered to measure water speed below the turbulent boundary layer of the hull, resulting in accurate clean-water readings.

Ultrasonic sensing is a proven technology that has been used on ships for nearly 20 years. Building on this technology, Airmar developed an advanced design which operates at a higher-frequency, enabling reliable operation in both salt and fresh water. The state-of-the-art processor in the CS4500 calculates speed every half second, so it can respond to rapid changes in vessel speed. This translates into the very reliable and accurate ultrasonic speed sensor.

• 4.5 MHz Frequency
• 0.1 to 40 knots Speed
• Unparalleled accuracy as low as 0.1 knots
• Designed for use with all types and sizes of sailboats and powerboats
• No moving parts
• Makes retrofitting a breeze—the retractable insert fits most Airmar 51mm (2") housings
• Bronze housing
• Built-in temperature sensor