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Product Description

Airmar’s patented UST850 just turned your maintenance time into more cruising time—and made your boat smarter too. Get ultrasonic speed and temperature in a single thru-hull housing with no moving parts. This sensor is a high-precision, low-maintenance solution for use on power and sail boats of all types and sizes. Say goodbye to paddlewheel maintenance and hello to Smart™ technology, from the company who invented the Smart™ Sensor.


  • Ultrasonic speed and fast-response water-temperature sensing
  • Single housing with no moving parts—no paddlewheel
  • Advanced filtering and sampling rates for increased accuracy at all speeds
  • Adapts automatically to increases in speed so accuracy remains constant
  • Retractable plastic insert in a low-profile bronze housing with a water valve
  • Retrofits into Airmar’s plastic (P17) or bronze (B17) housing
  • Airmar's Smart™ Sensor technology


  • Brand: Airmar Technology
  • Acoustic Window: Urethane
  • Cable-Length: 6 m (20') NMEA 2000® cable
  • Common Use: Cruising/Racing Sailboats, Leisure/Yachting, Fishing
  • Country of Origin: USA
  • Data Rate: Up to 10 times per second
  • Display Connector: N2 Micro
  • Hole Size: 51 mm (2"), Stainless steel housing in metal hull—57 mm (2-1/4")
  • Housing Material: Stainless Steel
  • Hull Material: All hull materials
  • Mounting Style: Thru-Hull
  • NMEA 2000 LEN: 7
  • Power Rating: N/A
  • Protocol Output: NMEA 2000®
  • Retractable housing: Yes
  • Retrofits: Retrofits into AIRMAR P17, B17, P617V housings
  • Single or Dual Frequency: Conventional Single Frequency
  • Speed Range: 0.1 to 50 knots (0.1 to 57 MPH)
  • Temperature Accuracy: ±0.5°C (±1.8°F)
  • Tilted Element: No
  • Transducer Functions: Speed, Temperature
  • Usable Shaft Length: 57 mm (2.25")
  • Voltage: 9 to 16 VDC
  • Water Temperature: -10° to 40°C (14° to 104°F)
  • Weight: 1.7 kg (3.7 lb.)


Shipping is fast and FREE across the USA for all orders $199 or more. For more details about shipping see the full shipping page here.

We offer 30 Day Easy Returns. If you decide you don't need a product we'll take it back so long as it is in original and re-saleable condition. See the full details here.

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