Cayman Islands advisory: GPS week rollover impact on JRC equipment

Eda Zenic -

The Maritime Authority of the Cayman Islands (MACI) has issued Guidance Note 07/2024 to inform ship and yacht owners, managers, and masters about an upcoming GPS Week Number Rollover event that will impact specific JRC equipment on 8 September 2024.

This rollover is a technical event where the GPS system's internal clock resets, which will cause certain devices to revert their date to 23 January 2005, a date 19.6 years in the past. This anomaly could result in incorrect date displays and disruptions in communication functions.

Affected Equipment

The equipment identified as being vulnerable to this issue includes various types of JRC (Japan Radio Company) devices commonly used in maritime operations. These are:

  • AIS (Automatic Identification System):
    • JHS – 182
    • JHS – 183
  • GPS Navigation Systems:
    • JLR – 7800
    • JLR – 7900
  • GPS Receivers:
    • JLR – 4341
  • GPS Compasses:
    • JLR – 21
    • JLR – 31

Manufacturer's Advice

JRC, the manufacturer of the affected equipment, has released a notice providing more detailed information on how this rollover will impact their devices. The notice can be accessed on their website at the provided link: JRC Notice.

Required Actions

The Maritime Authority advises all owners, managers, and masters of Cayman Islands ships and yachts to:

  1. Identify Affected Equipment: Review the equipment installed on their vessels to determine if any of the listed JRC devices are present.
  2. Contact JRC Service: If affected equipment is found, it is recommended to get in touch with a JRC service agent or sales representative to discuss the necessary steps. This may involve performing a software update or, if necessary, replacing the equipment with newer models to ensure continued proper functioning and compliance with maritime safety standards.