March 2026: Commercial vessels in the Strait of Hormuz—carrying 20% of the world’s oil—have nearly ground to a halt in the face of increased GNSS interference from the Iran war. GNSS spoofing has made ships appear to move in circles, even when not moving. For a single ship with an experienced crew, visual cues may be sufficient to transit the Strait, but this issue multiplies when ships’ automatic identification systems (AIS) rebroadcast their erroneous positions.
“It’s just chaos on your electronic chart display,” said the RNL’s Dr. Todd Humphreys. These false positions are “picked up by AIS receivers across the coast, and that’s what other ships see.” With over 100 untracked vessels moving through the Strait—which spans 21 miles at its narrowest—risk increases immensely. “These are enormous ships that take kilometers to slow down and change direction,” Dr. Humphreys continued. “Very few captains would be willing to put a supertanker through that narrow strait.”
Dr. Zak Kassas, RNL alumnus and professor of electrical engineering at the Ohio State University, has been developing alternative navigation systems that exploit less-frequently jammed signals of opportunity, such as cellular signals and LEO megaconstellations. To this, Dr. Kassas said, “When we started, it was sort of a nice thing to have. But now, it is a pressing need. It could be a life-or-death situation.”
To learn more about the state of navigation in the Strait of Hormuz, read the more detailed discussion with Scientific American.
