USCG issues advice on GPS Rollover

Malcolm Latarche
Malcolm Latarche
ShipInsight

25 March 2019


Next month’s rollover of the GPS system and its potential to affect navigation and other systems on ships has prompted the USCG to issue some advice on the problem. While positioning may not be affected, reporting of times and position on automatic systems such as oil water separator operation may give false results.

The Rollover is caused by the computer timing system used in GPS equipment which is likely to reset to a point in 1999 on or around 6 April this year. The issue will mostly affect systems over ten years old. Problems may be avoided by a firmware upgrade to the equipment.

The Coast Guard Navigation Center published a special notice to mariners that outlines the details of the GPS Week Number Rollover which can be here.

To best prepare for the rollover event, users of GPS equipment who are concerned should update their firmware or contact their equipment manufacturer to ensure their equipment is ready for this event. Additional information about GPS and the GPS Week Number Rollover can be found on GPS.gov or in a recent Department of Homeland Security Memorandum.