The Strait of Hormuz began its first day of commercial reopening on June 18, following the signing of a U.S.-Iran memorandum of understanding on June 17. According to maritime intelligence firm Windward, 18 transits were recorded across the June 17 to 18 window — the highest single-window count recorded during the conflict.
Windward’s analysis describes the current situation as one of “cautious momentum rather than full normalization,” with legitimate commercial vessels, sanctioned tonnage, and unresolved military activity moving through the same corridor simultaneously.
Chinese-Affiliated Vessels Lead the Way
Of the seven vessels documented transiting in the morning window on June 18, five were Chinese-linked, according to Windward. The cohort included a Hong Kong-flagged MR tanker owned by Chinese government-controlled COSCO, a Hong Kong-flagged supramax bulk carrier, a Panama-flagged bulk carrier with Chinese owners and crew, and a China-flagged Panamax bulk carrier. These vessels had been stranded inside the Arabian Gulf for between 109 and 128 days since the conflict began.
European tonnage was also among the early departures. Windward reports that a France-flagged LNG carrier transited outbound, noting its diplomatic significance given that French President Emmanuel Macron was present alongside President Trump at the MoU signing. An Italy-flagged vehicle carrier was also among the first movers.
Three Saudi-flagged supertankers carrying approximately six million barrels of crude oil transited the Strait in the hours following the signing — two of which had been operating dark since mid-April — representing what Windward describes as the largest single departure through the corridor in weeks. All three transited with AIS off.
Sanctioned Fleet Reconstituting in Parallel
While legitimate commercial traffic was restarting, Windward’s reporting makes clear that Iran’s sanctioned oil export network was reconstituting simultaneously and at pace.
Three National Iranian Tanker Company (NITC) vessels ended months-long dark periods at Chabahar on June 16:
- DIONA (IMO 9569695) — ended a 94-day dark period
- HERO 2 (IMO 9362073) — ended an 81-day dark period
- SONIA 1 (IMO 9357365) — ended an 81-day dark period
Six additional U.S.-sanctioned Iran-trading tankers — comprising one VLCC, three LPG carriers, and two Suezmax tankers — departed long-running anchorages off the Riau Archipelago in the Strait of Malacca and are now transiting westbound toward Iran, according to Windward.
Also notable, Windward reports that a Panama-flagged vessel classified as a “zombie vessel” — with no verified owner, operator, or valid registry — transited outbound in the same 24-hour window as legitimate commercial first movers, alongside an IRISL-affiliated cargo vessel.
Unresolved Military Activity and Mid-Strait Holdouts
The operational environment remains complex. Windward reports that more than 80 IRGC high-speed craft were observed moving through the Kharg Island waiting area in an unusual, undirected pattern — weaving between stationary tankers with no clear heading, no convoy formation, and no consistent speed. This behavior had not been previously recorded at that location.
The CMA CGM SAN ANTONIO, a container vessel boarded and looted by IRGCN small craft in late May, remains stationary mid-Strait and has not moved since that incident, according to Windward. The Traffic Separation Scheme remains uncleared, with no minesweeping operations yet underway.
Does This Matter to You?
The reopening of the Strait of Hormuz is a significant development with direct bearing on global crude oil flows, LNG movements, bulk commodity shipping, and vessel scheduling across routes through the Arabian Gulf and Indian Ocean. The presence of sanctioned vessels alongside legitimate commercial traffic in the same transit window creates heightened exposure for anyone operating in or adjacent to the corridor — from cargo scheduling and port planning to sanctions compliance screening and insurance assessments.
Windward’s reporting highlights that the Traffic Separation Scheme remains uncleared of mines, a detained vessel remains mid-Strait, and IRGC small-craft activity continues at Kharg Island. These conditions mean the risk environment is actively transitioning, not resolved. Windward states that “the full picture of any post-conflict Strait will take weeks, not days, to settle.”
Gulf Bunkering does not provide operational or security guidance. This article is for informational purposes only. Operators should consult flag state authorities, P&I clubs, and relevant advisories for decisions relating to transit planning.
Sources: Windward Maritime AI™
