Gyro & Heading Systems

Why accurate heading matters

A dedicated heading sensor exists because a GPS course over ground is not the same as the way the bow is actually pointing, and the difference matters for radar overlay, autopilot steering and any stabilised camera or antenna on board. Fluxgate compasses are simple and affordable but can be thrown off by nearby metal or magnetic fields, satellite compasses use two GPS antennas to derive true heading independent of magnetism, and gyro-based sensors add fast, low-latency rate data that a compass alone cannot provide.

Mounting position matters as much as the sensor type: keep any compass well away from speakers, engines and large metal fittings, and follow the manufacturer's levelling and calibration procedure exactly, since a heading sensor fitted out of level introduces a steady error the system cannot correct for. Most current units share heading data over NMEA 2000, so check your radar, autopilot and plotter can all receive it on the same network before choosing a sensor.