The Pakistan‑flagged tanker Shalamar left the Persian Gulf on Thursday.
Shalamar's unusual crossing
The Aframax tanker Shalamar transited south of Iran's Larak Island late on Thursday after loading about 450,000 barrels of crude at Das Island in the United Arab Emirates, ship‑tracking data show.
The vessel signalled Karachi as its destination and was only half full when it sailed into the Gulf of Oman.
That exit is notable because it was the first crude‑laden departure through the Strait of Hormuz since a US naval blockade came into effect earlier this week, a move that now requires clearance from both Iranian and US authorities before vessels can move oil out of the Persian Gulf.
Traffic through Hormuz has been tiny
Ship movements through the strait have fallen sharply. Transits have largely been in single digits since strikes at the end of February triggered heightened military deployments by the US and allied navies.
Some vessels tried to cross and then turned back.
US Central Command said 14 vessels reversed course over three days, underscoring how constrained shipping remains as owners and insurers weigh the risks of passage.
Who’s moving oil — and why it matters
Maritime data collected since early March shows most ships getting through Hormuz have links to Iran, according to Lloyd's List Intelligence analysts. Their analysis found that a large share of recent transits involved vessels owned by Iran, calling at Iranian ports or tied to the so‑called shadow fleet that carries sanctioned oil.
That shadow fleet has accounted for an especially large share of movements in recent weeks, and analysts say vessels tied to Iran have used islands in the strait — particularly Larak — as control points when managing traffic.
Iran has said the strait is closed only to ships belonging to or linked to the US and Israel. President Donald Trump said recently that Tehran had offered him a "present" by allowing Pakistan‑flagged tankers to pass, while Pakistan announced a bilateral deal with Iran to permit two ships per day for 10 days. But tracking sites show no broad increase in Pakistan‑flagged traffic through Hormuz.
Why Shalamar’s passage stands out
Shalamar is unusual on several counts. It attempted a crossing on Sunday, then turned back as peace talks broke down. It then completed a short voyage into the Persian Gulf and, within days, headed out again carrying crude.
Only a handful of non‑Iranian tankers have managed to leave the Gulf with cargo since the recent spike in tensions; three very large crude carriers slipped out last week with non‑Iranian cargoes, but such movements have been the exception.
The relative scarcity of departures reflects tightened naval patrols and the practical complexity of obtaining clearance from two opposing authorities — Tehran and Washington — in a volatile environment.
Flows and capacity before the blockade
Until the blockade, Iran's own fleet had continued to move oil, providing a trickle of exports that amounted to roughly 1.7 million barrels per day in March, data show. That flow has largely stopped as both sides reassess options and diplomats talk about fresh rounds of negotiations.
The pause is having knock‑on effects. Tanker owners are weighing the legal and insurance risks of transiting the strait. Some are sitting idle. Others are seeking alternative routings that add days and costs to voyages.
Market and shipping implications
The Strait of Hormuz is a chokepoint for global energy flows. Even small dislocations there raise shipping costs and push risk premiums higher across freight and marine insurance markets.
For refiners and traders, uncertainty about reliable access to Persian Gulf crude can force sourcing shifts and shorter supply covers. That tends to push freight rates up and widen the gap between nearby markets and distant hubs.
Insurers have already been adjusting coverage and premiums for vessels operating near the Gulf. Shipowners face the choice of paying higher fees, accepting longer voyages around the Cape of Good Hope, or finding short‑term charters that can absorb the added cost. All of those options add to the landed cost of crude and refined products.
Sanctions, "shadow" fleets and insurance risks
Another factor is the so‑called shadow fleet — older tankers and vessels that have been repurposed to move sanctioned cargoes with less transparent ownership and flagging. Lloyd's List Intelligence data show that these vessels have played a dominant role in recent transits.
That activity complicates underwriting. Insurers look at a vessel's ownership, trading history and flag state. Where ownership is opaque, insurers demand higher premiums or exclude cover altogether. When major underwriters step back, banks and trading houses become more cautious about financing shipments.
Diplomacy, deterrence and commercial choices
Diplomatic signals have fed commercial caution. Iran has alternated between threats to close the strait to certain flags and limited permissions for vessels it deems acceptable. The US has used naval patrols and the threat of interdiction to try to prevent sanctioned exports and to deter hostile action.
That mix leaves shipowners in a bind: they're being asked to secure two clearances that may have conflicting conditions. Many are choosing to wait for clearer rules or for government‑backed convoy arrangements, where naval escorts reduce risk and help insurers feel more comfortable offering cover.
What this means for traders and refiners
Refiners that depend on Gulf crude may have to shift to cargoes that can be delivered on a reliable basis. Traders who usually play cargo spreads might widen their hedges. And charterers that need to load quickly are likely to pay a premium to secure available tonnage that can operate around the Gulf.
Market participants are also watching for whether Pakistan will push for more frequent clearances for its flag — and whether Tehran will stick to a narrow list of acceptable vessels. So far, the data don't show a sustained increase in Pakistan‑flagged transits.
Near‑term outlook
For now, the flow through Hormuz is low and erratic. Shipowners will keep assessing risks against potential rewards. Military moves and diplomatic talks will continue to set the tempo.
What traders and shipping firms are pricing in is more than the lost barrels — it's the cost of moving oil under duress: longer voyages, higher insurance, and the potential for rapid policy shifts that can strand vessels or cargoes.
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US Central Command said 14 vessels turned around in three days.
This article was created with AI assistance.
