Furuno SCX21 Satellite Compass – NMEA 0183

For boats demanding extreme heading accuracy for their NMEA 0183 network, the Furuno SCX21 satellite compass is the definitive answer. This is not a magnetic compass. It is a high-precision multi-GNSS sensor that uses a sophisticated quad-antenna array to calculate true heading, pitch, roll, and heave data with incredible precision. Because it derives heading from satellite signals, it is completely immune to the magnetic interference from steel hulls, engines, or electronics that plagues traditional compasses. The output is a clean, stable data feed for autopilots and chartplotters.

The unit’s brainpower lies in its advanced inertial and satellite vector stabilization, which actively compensates for the vessel’s every movement. This solid-state design means there are zero moving parts to wear out or fail in rough seas. Housed in an IP56-rated enclosure, it is built to live on a pole mount exposed to the elements, operating flawlessly from a frigid -25°C to a blistering 55°C. It delivers a level of data purity that magnetic compasses simply cannot match.

Helm Use and Readability

You do not read the SCX21 directly. It is a data source that feeds your other electronics. Its primary job is to make your autopilot perform flawlessly, allowing it to steer straighter courses with fewer, smaller corrections, which saves fuel. It also provides a rock-solid heading reference for your radar, which is essential for accurate target tracking with features like MARPA. The result is a more capable, more integrated, and safer electronic navigation suite at your helm.

Why Choose the Furuno SCX21 High-Precision Multi-GNSS Satellite Compass and Heading Sensor

You choose the SCX21 satellite compass when “good enough” heading data is not good enough. It is a critical upgrade for commercial vessels, serious sportfishing boats, or any captain who relies heavily on their autopilot for long passages. Its immunity to magnetic interference and its ability to provide pitch, roll, and heave data make it a fundamentally superior sensor for stabilizing modern sonar and radar systems. It is an investment in data quality that pays off in performance and safety.

Warranty and Support

Furuno covers this advanced sensor with its standard 2-Year Manufacturer’s Warranty against defects. For complex questions about integration with your specific NMEA 0183 equipment, provides expert pre-purchase support. Their team verifies the contents of every package before it is shipped. We highly recommend reviewing the complete warranty policy details available on before placing your order.

Before Ordering the Furuno SCX21 High-Precision Multi-GNSS Satellite Compass and Heading Sensor

Before buying, identify a suitable mounting location on your boat that has a completely clear view of the sky in all directions. Confirm your autopilot or chartplotter has an available NMEA 0183 input port capable of receiving heading data. You will also need to purchase the correct length of data cable separately to connect the sensor to your helm electronics, so measure the required cable run carefully.