Specifications:

Supply Voltage:

10.0 to 16.50 VDC 0.018 amps nominal.

Operating temperature:

0 to 50 deg Celsius ( 32 to 122 deg Fahrenheit).

Size:

50 x 35 x 30 mm (2 x 1.4 x 1.2 inch)

Input:

$GPRMC NMEA 0183 data sentence from a GPS (GPS not provided).

Output:

Analog paddlewheel signal 22,000 pulses per nautical mile.

Speed Range:

0.00 to 60.00 knots with 0.01 knot resolution.

Output Voltage:

0 to 12V nominal square wave.

Advantages:

No speed transducer required.

No extra hole(s) in your boat.

No fouling or cleaning of the paddle wheel.

Gives speed over the ground.

Unaffected by water currents.

More reliable than a paddlewheel.

Usually more accurate than a paddlewheel.

Accurate down to 0.01 knots.

Accurate up to 60.00 knots.

0.01 knot resolution.

Inexpensive.

Good backup if your paddlewheel suddenly stops working.