AXSMarine AIS-derived transit data, collected continuously from March 1 through April 21, 2026, documents how the Strait of Hormuz operated — and who was willing to use it — in the weeks after the conflict began.
From stillness to structure
When we published When the Gulf Stopped in early April, the defining feature of the Strait of Hormuz was its absence. The crossings collapsed to nearly zero in the first days of March. The 353 multi-purpose dry bulk vessels confirmed in the Gulf by March 5 had nowhere to go. After seven weeks of continuous AIS tracking, traffic has not recovered in any meaningful sense. What has emerged instead is a class corridor: a thin one, defined less by commercial logic than by risk tolerance, convenience science, and proximity to the sanctioned fleet.
During the entire post-conflict period from 1 March to 21 April, AXSMarine recorded 446 confirmed transits across the dry bulk, tanker, gas tanker and container ship sectors – an average of 8.6 per day, versus a pre-conflict baseline of 115.7. This figure hides significant variation from one phase to the next, from a low of 6.6 per day in March to a brief peak of 28 crossings on one exceptional day in late April.
March: Remaining fleet
The first operators to move in March were Greek Panamax ship owners who were under severe commercial pressure – ships that had completed unloading cycles and needed to exit. The Georgia T, Minoan Sky, Star Gwyneth, and Minoan Dignity all crossed overseas between 13 and 16 March, followed by Chinese-operated Panamax aircraft including Belian Star and Broad Reach. The common thread was size and type of tonnage: 70-85 thousand dwt bulk carriers were engaged in the grain and fertilizer trade and were far behind their next composition. These were not operators scheduling new installations through Hormuz, but rather filling in and out of existing installations.
In the tanker sector, structural signs of the disabled corridor were already visible. Of the 67 tanker crossings recorded in March, 39 of them — fully 58% — involved sanctioned vessels, a ghost fleet or murky ownership files. Transparent, Western-flagged operators accounted for just 21% of tanker movements in March. Adjacent and opaque sanctioned fleets – sanctioned fleets and ghost fleets – were maintaining the thin thread of flows of crude oil and products abandoned by traditional operators.
Gas tanker traffic was relatively weak: 21 crossings versus the February baseline of 12.6 per day. The most notable development has been the emergence of Indian-flagged LPG tankers – BW ELM, BW TYR, PINE GAS, JAG VASANT and SHIVALIK – operating under the diplomatic exemption declared by Iran which includes India, China, Russia and Pakistan. Their continued presence, against the backdrop of the dominance of sanctioned fleets elsewhere in the sector, reflects a fleet operating under a different risk and legal framework to the rest of the market.
Container ships recorded the most complete withdrawal from any sector. Of the crossings that took place on March 27, half involved Iranian-flagged ships or Iranian-owned ships on internal routes. The only Western airline operator to move was ASTRID MAERSK (190,567 dwt) on 1 March – the last day before the commercial withdrawal became total. The COSCO giants CSCL INDIAN OCEAN and CSCL ARCTIC OCEAN (both 184,320 dwt) transited on 30 March; No similar ships followed.
April: A passage, not a recovery
The ceasefire announced on 7 April changed the operational environment without restoring normal conditions. The April 1-12 period averaged 11.1 and 13.2 crossings per day respectively, a modest improvement over March but well below any definition of commercial normality.
The most significant tanker movement of the entire post-conflict period occurred on 11 April: four VLCCs transited in one day – COSPEARL LAKE (299,118 dwt, Chinese-owned), HE RONG HAI (320,612 dwt, Chinese-flagged), SEREPHUS (309,396 dwt, Greek-owned) and MOMPASA B (299,392 dwt, Greek-flagged). owned by Greece). DWT, owned by Korea). The concentration of four VLCCs on a single day suggests coordinated movement through what operators saw as a short-term safe window – a pattern consistent with the tolling phase imposed by the IRGC in March, and with the broader behavior of an industry that has learned to read the corridor’s risk signals carefully.
When the US blockade of Iranian ports took effect on April 13, traffic fell to 9.2 crossings per day over four days. Notably, Iranian-flagged vessels continued to transit throughout: CLAVEL (50,072 dwt chemical/oil tanker) bound for Chabahar on 17 April, and NASHAT (23,116 dwt MPP) on 16 April. The stated scope of the blockade — restricting ships entering or leaving Iranian ports while preserving freedom of navigation for non-Iranian ports — created an ambiguity that operators of all nationalities were actively navigating.
72 hours set period: April 17-19
The most volatile sequence through seven weeks of data is compressed into three days. On April 17, Iranian Foreign Minister Abbas Araqchi announced that the strait was open to all commercial ships for the duration of the ceasefire in Lebanon. Oil prices fell by about 11%. In the AIS data, the effect was immediate.
April 18 recorded 28 crossings – the highest single-day level since March 1, the last day of regular trading. Each segment recorded its highest daily count following the siege simultaneously. FPMC C LORD (301,861 dwt, Taiwan-owned VLCC) transited offshore alongside DESH GARIMA (114,790 dwt, Indian-flagged) and NAVIG8 MACALLISTER (75,618 dwt, Singapore-owned) – the most significant return of major commercial operators to the corridor since early March. In dry bulk, nine crossings included Greek-owned Panamaxes DANAE (81,252 dwt) and CECI (82,338 dwt) alongside vessels owned by the UAE and Kuwait, and in gas, seven crossings achieved the highest daily tolls in the sector post-conflict, although dominated by sanctioned fleet operators including NV AQUAMARINE, GAS LEADER and RAINE.
The window lasted for hours. President Trump confirmed that the US blockade on Iranian ports remains in effect. Iran retracted its announcement. The IRGC announced that the strait had returned to its previous state, and IRGC gunboats reportedly fired on at least one commercial ship. On April 19, the USS Spruance intercepted and seized the Iranian-flagged cargo ship Tosca in the Gulf of Oman – the first ship to be captured in the conflict. That day, two scores were recorded in all segments.
The number of crossings in the three days following the seizure averaged 6.0 times per day – the lowest sustained rate since late March. The average reopening window was 20.5.
Which is still moving
Ship-level data over the entire period tells a consistent story about which operators remained active and which did not.
In dry bulk, Greek owners accounted for 55 of the 180 transits from March 1 to April 21 — more than any other nationality, nearly double the Iranian number of 34, and well ahead of the 23 Chinese operators. But the nature of that Greek involvement is important: These are almost entirely outbound Panamax and Kamsarmax bulk carriers, which complete legacy unloading operations, not operators. Committed to a new cross-Strait route. The size distribution – 68 vessels in the 25-55 thousand range, 52 in the 55-82 thousand range, and 17 above 82 thousand – exactly reflects the Supramax and Panamax trade that dominated commodity flows in the Gulf before the conflict.
In oil tankers, operators subject to sanctions and unclear regarding ownership were a majority or near-majority in every period except the brief reopening period. Of the 32 VLCC and Suez Max crossings (over 100,000 DWT) recorded from March to April 21, the majority had ambiguous or sanctioned ownership structures.
The April 18 spike is the clearest indication in the data about what demand actually looks like. When both governments indicated at the same time that the strait was open, 28 ships crossed in one day. Operators are placed. The load was ready. The resumption of large-scale commercial traffic is not related to the availability of ships or market appetite.
Container ships remain the most obvious case. TEMA EXPRESS (50,790 dwt, German-owned, Liberian-flagged) surfaced on April 21 after a month-long AIS outage — one data point from a ship whose schedule missed the passage for weeks. Its re-emergence highlights the latent demand and the conditions that currently prevent it from being met.
What the data shows
Seven weeks later, the Strait of Hormuz is operating at about 7% to 9% of its pre-conflict usage rate during stable periods, with short spikes when political signals are consistent and sharp contractions when they are not. The remaining corridor is dominated by operators with greater risk appetite, diplomatic exemptions, or ownership structures that make the calculus different from that facing major commercial fleets.
The April 18 data remains the most important observation: Given the signal, the market responded within hours. The question of when normal traffic will resume is entirely political. The commercial infrastructure needed to support it already exists.
Data source: AIS-derived transit data AXSMarine, 1 March to 21 April 2026. All figures are based on AIS-visible transits only and exclude vessels operating in a confirmed power outage situation. Ship-level transit data is available upon request.
Source: AXSMarine AIS, Signal Group
