Low-Cost Sensor The S300, ST300 speed and temperature sensors are Airmar’s lowest cost and shortest, thru-hull, speed sensors. As part of Airmar’s Shorty™ Series, they are designed for boats with low headroom. The plastic P371 low-profile outer housing option is nearly flush and minimizes drag with only 5 mm (2/10”) extending outside the hull. The plastic P398 countersunk outer housing version mounts flush, eliminating turbulence for more accurate speed readings. Thru-Hull Low-Profile Shorty™ Series Speed Sensors Applications • P371 housing—cruising sailboats and planing powerboats • P398 housing—racing sailboats and high-speed powerboats Features • Shorty series low-profile is designed for fiberglass and aluminum hulls with low headroom • Right angle cable exit offers low headroom and protection when transducer is stepped on • Self-closing sea valve reduces waterflow when paddlewheel is removed for cleaning • Total height is only 75 mm (2.96”) • Fins on sides of paddlewheel cavity provide improved accuracy in cross-flow conditions • Housings are ABYC H-27 compliant • Blanking plug is supplied with each unit • Included rubber washer allows tightening of the hull nut to irregular hull surfaces • P398 housing installation requires special cutter • Speed only or Speed and temperature • Available in

Technical Information Per Nautical Mile P371 housing with fins P371 housing without fins P398 housing with fins P398 housing without fins Nominal Pulse Rate Options • Temperature sensor • Intelligent circuitry for linearity correction and jitter control • No fins alongside paddlewheel • Two-wire speed circuit • Pulse division circuitry or other pulse rates • Over-voltage protection (OVP) Weight: 0.6 kg (1.3 lb) Speed Range: 0.1 knot to 40 knots (0.1 MPH to 46 MPH) Supply Voltage: 5 VDC to 25 VDC Supply Current: 100 mA at 12 VDC Hole Diameter: 51 mm (2”) Sensor Cable Length: 10 m (33’) standard...