Commercial vessel movements through the Strait of Hormuz began to recover on June 18 following the signing of a memorandum of understanding between the United States and Iran a day earlier, according to maritime intelligence company Windward.

Windward recorded 18 transits during the June 17-18 window, describing this as the highest single-window count since the conflict began. The movements included the first commercial ships stranded inside the Arabian Gulf to pass through the corridor following the disruption.

The initial group was led by Chinese-affiliated tonnage. Five of seven documented first movers were Chinese-linked, while European, Japanese and Saudi vessels were also among the early departures. Windward said the broader mix indicated that confidence was beginning to extend beyond shipowners with the highest tolerance for risk.

Three Saudi-flagged supertankers carrying an estimated combined cargo of about six million barrels of crude also transited the strait without transmitting their positions in the hours after the agreement was signed.

Windward reported that activity linked to Iran’s oil export network had started increasing before the signing. Three National Iranian Tanker Company vessels ended months-long periods without transmitted tracking signals at Chabahar on June 16. Six additional sanctioned tankers were reported moving westbound through the Strait of Malacca toward Iran after leaving long-standing anchorages.

Other sanctioned vessels were approaching the Strait of Hormuz and Bab al-Mandeb, according to the assessment. Windward also identified an outbound transit by what it described as a zombie vessel, alongside an IRISL-affiliated cargo ship, within the same 24-hour period as the first commercial departures.

Military activity remained a significant element of the operating environment. More than 80 Islamic Revolutionary Guard Corps high-speed craft were observed moving through the Kharg Island waiting area in what Windward characterised as an unusual and undirected pattern not previously recorded at that location.

Meanwhile, the CMA CGM SAN ANTONIO remained stationary in the middle of the strait. Windward said the vessel had been held there since it was boarded and looted by Islamic Revolutionary Guard Corps Navy small craft in late May.

The simultaneous movement of regular commercial ships, sanctioned tonnage and military craft points to a complex and still uncertain reopening. Windward assessed the June 18 developments as cautious momentum rather than a full return to normal operating conditions in the strategically important corridor.