The US-Iran war has caused a "structural shift" in the commercial, legal, and operational aspects of vessel transit through the Strait of Hormuz, Kpler said on Friday.
The US blockade has significantly cut the number of visible crossings through the passage. Kpler noted that crossings totaled 189 during the first 12 days of the campaign, a 92% plunge relative to the 2,310 recorded during the June 2025 conflict.
The research firm said that around 500 vessels remain stuck in the Gulf.
The recent crisis "has produced a passage environment where vessels may move but their movements cannot always be trusted, verified or defended," shifting away from the conventional assessment that simply relies on whether the Strait is open or closed, Kpler said.
This vessel "behavior" changes how maritime risk and compliance processes should evolve, according to the research firm.
Counterfeit satellite signals, or GNSS spoofing, peaked at above 3,000 in a single day in early March following the onset of the Middle East conflict, Kpler data showed, with only 6.4% of observed vessel crossings between March 1 and May 19 using the route designated by the International Maritime Organization's Traffic Separation Scheme.
With these observations, the research firm noted that a marine insurance provider's commercial terms "may make transit economically irrational," while "sanctions risks can crystallize at the point of coordination with Iranian authorities" even before a payment is made.
As such, Kpler highlighted that vessel behavior has become the primary signal for risk assessments, rather than political or diplomatic announcements.