Grounding Incident Due To GPS Jamming: Lessons Learned And Risk Assessment


  • A vessel ran aground due to GPS jamming, leading to navigational challenges exacerbated by equipment malfunctions and distractions on the bridge.
  • Key factors contributing to the incident include inadequate response to GPS malfunction, lack of navigational warnings, and distractions from recurring alarms.
  • Lessons learned from the incident highlight the importance of crew training, procedural guidelines, and contingency planning to mitigate similar risks in the future.

The vessel, navigating in an area with heightened security considerations, experienced GPS jamming, leading to inaccurate position readings and subsequent grounding on a reef. Despite the malfunction, the crew continued navigating toward the pilot station, relying on alternative position-fixing methods.

Contributing Factors

Several factors contributed to the incident, including:

1. Failure to recognize compromised GPS environment and respond effectively.
2. Lack of navigational warnings regarding GPS interference in the region.
3. Distractions caused by recurring alarms on bridge equipment connected to GPS.
4. Inadequate bridge watchkeeping levels and split attention between navigation and alarm acknowledgment.
5. Insufficient familiarity with alternative position-fixing methods and contingency planning.

Lessons Learned and Risk Assessment

To prevent similar incidents, the following measures should be considered:

1. Crew Training and Familiarization

  • Provide training to recognize and respond to compromised GPS environments.
  • Ensure familiarity with alternative position-fixing methods and practice them regularly.

2. Procedural Guidelines

  • Incorporate guidelines in the safety management system for identifying and responding to GPS malfunctions.
  • Conduct voyage-specific risk assessments, especially when calling at ports in high-security risk areas.
  • Formulate and verify the effectiveness of contingency plans for GPS failure through drills.

3. Alarm Management and Bridge Manning

  • Address automation and confirmation bias to minimize distractions from recurring alarms.
  • Review bridge manning levels to ensure adequate attention to navigation tasks and alarm acknowledgment.

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Source: Gard