In normal ship navigation up until recently, the means used to measure the heading of a ship has been a gyrocompass or a magnetic compass. However, with the adoption of the installation requirements in SOLAS-V in July 2002, all passenger ships and all ships from 300 to 500G/T traveling international routes are required to carry a new directional sensor: a Transmitting Heading Device (THD). Since then, as the ISO standard for THDs, ISO-22090-3, has been adopted, THDs have been certified as MED devices, etc., use of GPS compasses with low price and high functionality has become widespread. Applications of this GPS compass in a variety of fields are drawing attention. This report introduces the JLR-21/31 GPS Compass, which has a high speed position updating function that primarily utilizes a heave measurement function, one example of GPS compass applied technology. Moreover, this report introduces a use example and an evaluation result based on data.