About 90 Ships Cross Strait of Hormuz as Iran Exports Millions of Barrels Despite War

Lead

Since the outbreak of the Iran war in early March, roughly 90 vessels — including at least 16 oil tankers — have traversed the Strait of Hormuz even as much commercial traffic has halted and the waterway was widely described as effectively closed. Maritime intelligence and trade analytics firms report Iran has exported more than 16 million barrels of oil since the beginning of March, with China the largest buyer amid Western sanctions. Some passages appear to have relied on diplomatic talks or covert routing; others used so-called “dark” transits to reduce visibility. The pattern has kept oil flowing while contributing to a spike in crude prices above $100 per barrel.

Key Takeaways

• At least 89 ships passed through the Strait of Hormuz from March 1–15, including 16 oil tankers, according to Lloyd’s List Intelligence.
• Kpler estimates Iran exported over 16 million barrels of crude since the start of March despite sanctions and military activity near key facilities.
• Daily vessel passage before the war was roughly 100–135 ships per day; recent traffic is a fraction of that level but not a full shutdown.
• About 20 vessels have been attacked in the broader area since early March, contributing to elevated insurance and risk premiums for shippers.
• Some transits were classed as “dark” — vessels switching off tracking or obscuring ownership — which analysts link to Iranian-affiliated operations or sanction evasion.
• State-owned ships from India and a Pakistan-flagged tanker also moved through the strait following diplomatic engagement with Tehran.
• Oil prices have risen more than 40% since the conflict began, topping $100 per barrel and prompting U.S. calls for naval escort and other measures to stabilize markets.

Background

The Strait of Hormuz is a narrow chokepoint at the mouth of the Persian Gulf that historically handles roughly one-fifth of global crude flows. Control of or disruption to the strait reverberates through global energy markets because large volumes of Iranian, Saudi and other Gulf states’ oil transit that corridor. In early March, the onset of open hostilities led many commercial operators to suspend voyages through the area, citing direct attacks and the prospect of escalation.

Western governments imposed sanctions and warned ships away from Iranian waters, while Iran signaled it could restrict passage for vessels linked to the United States, Israel and their allies. At the same time, Iran retains major export infrastructure — including terminals and Kharg Island — that together with its naval posture give it leverage over who may pass close to its coast. That combination of infrastructure control, sea denial tactics and targeted diplomacy has produced a patchwork of permitted and restricted movement through the strait.

Main Event

Between March 1 and March 15, Lloyd’s List Intelligence recorded at least 89 transits through the strait; roughly 20% of those vessels were assessed as Iran-affiliated, with the remainder carrying links to countries such as China and Greece. Analysts flagged 16 of those transits as oil tankers. The overall daily vessel count is far below the pre-war norm of about 100–135 passages per day, but the presence of any tankers illustrates that exports have not been fully curtailed.

Maritime data provider Kpler estimated Iran has moved more than 16 million barrels of crude since early March, a volume that suggests Tehran has maintained a substantial export artery. Much of that oil is believed to have flowed to China, which faces fewer financial and legal constraints than Western buyers and has been the largest reported purchaser since sanctions tightened.

Some non-Iranian vessels also passed the strait after bilateral discussions. Two India-flagged LPG carriers owned by Shipping Corp. of India and a Pakistan-flagged tanker named Karachi transited the corridor in mid-March, reportedly following talks between those governments and Tehran. Analysts say such passages likely required diplomatic engagement or tacit Iranian acceptance to reduce operational risk.

Separately, U.S. officials publicly pressed allies and partners to deploy naval assets to re-open or secure the strait, while the U.S. also acknowledged allowing some Iranian tankers to sail in order to keep global supply channels functioning, according to a Treasury official’s interview cited by media.

Analysis & Implications

The pattern of selective transits suggests the strait is not uniformly closed but is being managed to favor Iranian exports and a narrow set of tolerated movements. That selective openness allows Iran to continue generating export revenue and to exert geopolitical pressure by constraining global supply enough to push prices higher. The effect is asymmetric: Tehran can impose pain through higher prices without fully severing a revenue stream that funds its operations.

For global markets, continued Iranian exports amid an overall traffic slowdown mean supply disruptions are uneven; buyers who can arrange politically negotiated shipments or who accept the higher risk premiums may secure cargoes, while others face shortages and price volatility. Insurance costs, rerouting expenses and detours around the gulf are likely to keep freight rates and end-user fuel prices elevated for the foreseeable term.

Diplomatic maneuvers are central to the flow of ships. States with closer ties or active negotiation channels with Tehran — notably China, India and Pakistan in recent reports — appear able to secure passage for state-linked vessels. That dynamic increases the value of bilateral diplomacy in energy security calculations and reduces the effectiveness of blanket sanctions unless enforced multilaterally and with naval guarantees.

Militarily, the U.S. strikes on Iranian facilities such as those on Kharg Island illustrate the tension between degrading Iran’s export-enabling infrastructure and avoiding moves that would further escalate and fully close the strait. If Iran deliberately limits tanker allowances to maintain upward pressure on prices, the global economic pain may continue while Tehran preserves leverage and revenue.

Comparison & Data

The table condenses reported figures from industry trackers and trade analytics: daily passage numbers reflect historical patterns, while the March 1–15 total is a count over that interval rather than a daily average. The >16 million barrels figure is an estimated cumulative export volume reported by Kpler and aligns with observed ship movements, though precise cargo ownership and end buyers involve further verification.

Reactions & Quotes

Industry and government actors framed the transits as evidence of a managed, selective corridor rather than an absolute closure.

“There has been continued resilience in Iran’s oil export volumes.”

Ana Subasic, Kpler trade risk analyst

Analysts at maritime intelligence firms suggested that deliberate routing and diplomatic engagement enabled some movements close to the Iranian coast.

“Iran may have effectively created a safe corridor with some ships passing close to the Iranian coast.”

Richard Meade, Editor-in-Chief, Lloyd’s List

U.S. officials framed limited allowances as a pragmatic choice to stabilize supplies while pursuing other policy levers.

“The Iranian ships have been getting out already, and we’ve let that happen to supply the rest of the world.”

Scott Bessent, U.S. Treasury (interview cited)

Unconfirmed

• Precise ownership and final buyers for every tanker counted in March are not publicly verified; some shipment records remain opaque and rely on indirect tracking.
• The extent to which vessel declarations of “all-Chinese crew” or Chinese links were coordinated with Beijing to reduce risk has not been independently confirmed.
• Public statements that the U.S. explicitly allowed Iranian tankers to transit require further documentary confirmation beyond media-cited interviews and official briefings.

Bottom Line

The available maritime and trade data indicate the Strait of Hormuz has been selectively permeable: Iran has preserved a meaningful export channel while overall commercial traffic declined sharply. That selective openness lets Tehran maintain export revenues and exert influence on global energy prices without fully reopening the corridor to normal traffic levels.

For markets and policymakers, the episode underscores the limits of unilateral sanctions and the importance of diplomacy, naval presence and insurance-market responses in managing energy security. Expect continued volatility in oil prices and targeted diplomatic efforts by governments whose vessels or citizens depend on Gulf energy supplies.

Sources

• AP News (news report)
• Lloyd’s List Intelligence (maritime intelligence)
• Kpler (trade data & analytics)
• MarineTraffic (ship-tracking platform)
• Financial Times (news/analysis)
• CNBC (news interview citation)
• ING (bank research note)