top of page
Search

Fighting Back Against GPS Spoofing and Jamming – A Turning Point for Maritime Navigation

  • Writer: Captain Cal Callahan
    Captain Cal Callahan
  • Sep 17
  • 3 min read
GPS Spoofing and Jamming

Back in May, I wrote about the MSC Antonia, a 304-metre container ship that ran aground near Jeddah after falling victim to GPS spoofing. That incident was a wake-up call for every ship operator still relying solely on GNSS to keep their vessels safe.

Since then, the risk picture has only grown sharper. Reports of GPS spoofing and jamming along the Southern U.S. border and interference in other strategic waterways are stark reminders that GNSS disruption is no longer theoretical — it’s happening, and it’s affecting shipping. The message is clear: our navigational resilience is being tested in the real world.



The Threat: GPS Spoofing and Jamming at Sea

  • Spoofing tricks your receiver with false satellite signals, making your vessel think it’s somewhere it isn’t — sometimes from metres to hundreds of miles off.

  • Jamming simply overwhelms GNSS receivers with noise, leaving the bridge crew with no satellite positioning at all.

Both create high-risk situations, particularly in restricted waters. If left undetected, spoofing can lead to groundings (as with MSC Antonia), while jamming can leave a ship without positional awareness in busy sea lanes — a dangerous combination when time and space to react are limited.



Jammertest 2025 – The Industry’s Proving Ground

From 15–19 September, the world’s most advanced GNSS interference testbed is live again at Andøya, Norway. Jammertest 2025 allows controlled, large-scale jamming and spoofing attacks against real systems and vessels, so operators and equipment manufacturers can see exactly how their technology performs when the satellites go dark.

  • SAL Navigation is field-testing its SPU-200 solution, designed to detect and resist spoofing in real time.

  • AD Navigation AS is once again participating with its Independent PPU systems, which four years of independent testing show consistently outperform traditional SOLAS-class GPS/GNSS systems.


As my colleague Henry Fatiaki shared from the event:

“This year, 150 organisations from 24 countries have gathered, bringing together 386 participants to advance knowledge, share expertise, and test solutions in a unique environment. At AD Navigation AS we’re proud to continue our long-standing contribution to Jammertest. Our focus remains clear: systematic data collection, new in-depth analysis, and results that speak for themselves.”

This is not theory — it is where shipboard technology proves whether it can keep crews safe when everything goes wrong.



Lessons from the Field: Commissioning in Angola

Henry Fatiaki travelled to Angola to perform a commissioning for the AD Navigation AS Berthing Aid System and Qastor – Precise Piloting. Each commissioning project brings its own challenges, but also valuable lessons that help the team improve and grow.

Henry expressed his thanks to the Norway-based team and everyone who supported him onboard — their teamwork and quick problem-solving made all the difference. Every commissioning is an invaluable learning experience, strengthening both the solutions and the people behind them. Experiences like Henry’s remind us why it is so critical to keep developing resilient systems and skilled teams, ready for whatever operational challenges come next.



How Shipping Companies Are Fighting Back

The maritime industry is now taking active steps to defend against GNSS interference. Key initiatives include:

  • Resilient GNSS receivers – with anti-jamming antennas and multi-constellation capability (GPS, Galileo, GLONASS, BeiDou).

  • Independent pilotage units (PPUs) – like those from AD Navigation, which maintain situational awareness even during attacks.

  • Bridge team training – cross-checking positions with radar ranges, visual bearings, and inertial navigation systems.

  • Participation in live trials – like Jammertest, to validate both equipment performance and crew response procedures.

This combined approach — technology + training — is closing the gap between cyber threats and navigational safety.



Seamanship Still Matters

At Small Vessels Manual, we continue to teach and emphasise traditional navigation skills — because when satellites fail, your compass, radar, and chartwork will not.

These skills are not just regulatory requirements (AMSA still mandates paper chart navigation for Certificates of Competency), they are essential survival tools when operating in contested maritime environments. As I’ve said before, technology can fail — seamanship must not.



Looking Ahead

The results from Jammertest 2025 will shape the next generation of navigation systems, training programs, and operational procedures. But the human factor remains our first and best line of defence. Whether you are navigating a 300-metre container ship or a 12-metre coastal workboat — stay sharp, cross-check your position, and be ready to operate without GNSS when necessary. Because the sea will never forgive a navigator who blindly trusts a single source for position fixing.


For background on why this matters, revisit my earlier blog - An Avoidable Grounding in the Red Sea: GPS Spoofing and the MSC Antonia.



Capt. Cal

Sail your own course.



bottom of page