Why signal disruption makes tracking ships in Strait of Hormuz challengingpublished at 15:20 BST
By Shruti Menon
Tracking vessels around the Strait of Hormuz has become significantly more difficult as widespread global positioning system (GPS) disruptions are distorting how they appear on monitoring platforms like MarineTraffic.
BBC Verify has been looking into clusters of ships seemingly gathered in one location near Fujairah in the United Arab Emirates, as well as several disappearing altogether.
Dimitris Ampatzidis, maritime risk and compliance manager at intelligence firm Kpler, says it is “unusual” to see unrelated ships appearing to “converge into the same small cluster”. “In most cases, this does not mean the vessels are physically gathering there… it more likely indicates AIS interference.”
This is different from ships deliberately switching off their automatic identification system (AIS) transponders, which results in them disappearing from tracking feeds.
Interference produces false or erratic positions where ships may appear to jump locations suddenly, move in improbably straight lines, cluster together, or even show up on land.
Kpler data suggests the scale is significant, with around 2,000 vessels affected currently.
Samir Madani of TankerTrackers.com says such disruptions can be linked to defensive military activity seen near conflict zones and strategic choke points, where GPS is interfered with to deflect incoming threats like drones.