The Raymarine ST900/P120 brings next-generation paddlewheel technology to thru-hull speed and temperature sensing. The Gen2 Paddlewheel delivers accurate speed readings starting at just 0.3 knots and tracks smoothly up to 45 knots, outpacing earlier paddlewheel designs in both startup response and linearity. The low-profile housing sits nearly flush with the hull — only 5mm (3/16") protrudes below — minimizing drag on plastic or fiberglass/metal hulls. A built-in valve assembly reduces water ingress into the bilge during paddlewheel removal, and the ST900 transducer core drops directly into existing Airmar P120 and B120 housings for straightforward upgrades. Analog output makes it compatible with Raymarine i40, i50, iTC-5, and legacy instrument systems.

Specifications:

• Housing Material: Plastic
• Compatible Hull Material: Fiberglass/Metal
• Cable Length: 13.7M (45')
• Records: Speed and Temperature
• Hole Size: 51mm (2")
• Mounting Style: Low Profile Thru-Hull
• Speed Range: 0.3 to 45 knots (0.34 to 52 MPH / 0.55 to 83 KPH)
• Temperature Range: -10° to 40°C (14° to 104°F)
• Output: Analog — compatible with Raymarine i40, i50, iTC-5, and legacy systems
• Retractable design for routine paddlewheel maintenance
• ST900 core retrofits into existing Airmar P120 and B120 housings