GNSS jamming and spoofing: when a hypothesis gradually becomes a... fact

Over the past few days, there has been a noticeable increase in publications discussing GNSS interference, particularly GPS jamming and spoofing.

This brings me back to a case that is frequently cited in public and private reports, both in France and internationally: the collision that occurred off the coast of Oman between two vessels, which continues to be mentioned as an example of a collision “linked” to GPS spoofing.

What catches my attention is not the hypothesis itself.
GNSS interference in that region is documented and certainly not a new phenomenon. It obviously deserves to be taken seriously.

What raises more questions, however, is the way certain claims appear to circulate and strengthen as they are repeated.

A fairly typical dynamic often emerges:

• a report mentions a hypothesis without clearly detailing its sources or analytical methodology;
• the hypothesis is then repeated elsewhere, sometimes with stronger wording (“suspected”, “according to experts”, or even “certainly”);
• through successive citations, it gradually comes to be perceived as an established fact;
• retrospective re-analyses remain rare.

On LinkedIn and elsewhere, this dynamic is probably amplified by algorithms. It is also linked to a simple constraint: none of us has the time to thoroughly verify every source and every incident, myself included.

In the specific case of this collision, some publicly available information does suggest that one of the vessels involved experienced GNSS anomalies roughly 24 hours earlier.

However, based on the publicly accessible kinematic data, I do not see any element that would establish that electromagnetic interference played a direct role at the moment of the collision itself.

This does not mean that the hypothesis should be dismissed.

But establishing a causal link between GNSS interference and a collision normally requires a documented analysis: trajectory reconstruction, CPA analysis, manoeuvre chronology, operational context and application of COLREG.

To my knowledge, no detailed public technical analysis has yet been presented demonstrating such a link in this specific case.

We will therefore have to wait for the official investigation report. It may take time, but it is generally the healthiest way to establish the facts.

The purpose of this post is therefore not to determine the cause of this accident, but simply to recall a methodological point: when a hypothesis circulates without its analytical method being clearly explained, it can quickly turn — through simple repetition — into a widely accepted “fact”.

If anyone has access to a sourced and detailed technical analysis of this event concluding that GPS interference caused the collision, I would of course be very interested in reading it.

Sources

Joshua Minchin — Tankers collide in Strait of Hormuz – Updated: Navigational errors most likely cause of casualty; unlikely to be linked to the wider regional conflict, Lloyd’s List

My previous analysis: https://maritimeinfosec.org/maritime-collision-gnss-spoofing-wait-for-report/