Will number of transit calls through the Strait of Hormuz as reported by the IMF PortWatch be above 15 from Mar 23, 2026 to Mar 29, 2026?

The mathematical accumulation of transits in the first four days of the observation period provides a massive buffer against the late-week closure. Data from maritime intelligence platforms like Windward AI and S&P Global indicates a run rate of 3 to 7 ships per day between March 23 and March 26. At an average of just 4 ships per day, the threshold of 15 would be cleared before the Islamic Revolutionary Guard Corps escalated its blockade on March 27. Iran's policy prior to March 27 allowed for the selective passage of vessels from friendly nations, including China, Russia, and India. This controlled corridor ensured a steady floor of traffic. Even with major energy firms declaring force majeure, the movement of these non-aligned ships and the Iranian Ghost Fleet kept the waterway minimally functional. IMF PortWatch's tracking methodology provides a structural advantage for the YES side. The platform utilizes satellite tracking and a broader classification of vessels beyond just active Automatic Identification System transponders. PortWatch historically records higher transit counts than public AIS trackers, capturing ships that may have gone dark to avoid targeting.

The most significant risk to the YES case is the IRGC's March 27 announcement declaring an absolute closure of the Strait of Hormuz. The IRGC explicitly stated it would prevent any vessels from passing and reportedly forced three container ships to turn back that same day. If this blockade was perfectly enforced and retroactively applied to late March 26, the daily count for the final days of the period could legitimately be zero. The widespread use of AIS spoofing and GPS jamming in the region threatens the official count. While PortWatch uses supplementary data, it still relies heavily on AIS signals. If a significant portion of the early-week traffic navigated dark to avoid Houthi or Iranian targeting, the IMF's official reported number could diverge downward from the actual physical movement, potentially stranding the count just below 15. The definition of a transit call requires a complete passage. If ships entered the Strait early in the week but were forced to turn around or anchor due to escalating rhetoric ahead of the March 27 closure, they may not be counted as successful transits. A high number of aborted passages could artificially depress the official PortWatch count.