Oil, LPG tankers reach Mumbai despite US blockade of Strait of Hormuz — here’s how

The US push to choke the Strait of Hormuz has exposed the limits of naval enforcement in one of the world’s busiest shipping corridors, as tankers continue to find ways through.

Deployed east of the strait in the Gulf of Oman, the US Navy has struggled to make the blockade airtight. Dozens of vessels have reportedly slipped past since it began on April 13, including Indian-linked tankers.

One recent example is the vessel Desh Garima, which came under Iranian fire but still docked in Mumbai carrying 97,000 metric tonnes of crude from Ras Laffan. Reports suggest more than 30 tankers have crossed the strait despite the blockade, with tracking data cited by the Financial Times indicating at least 34 Iran-linked ships have bypassed restrictions.

According to India’s external affairs ministry, 14 Indian vessels are currently operating in the region.

Possible escape routes

Experts point to at least two viable pathways for ships exiting the Persian Gulf toward India:

• Makran coast route: Vessels can hug Iran’s coastline and transition into Pakistani territorial waters along the Makran coast, avoiding international waters where US enforcement is concentrated. This path, highlighted by analyst Jim Bianco and commentator Mario Nawfal, is technically feasible but politically sensitive for Indian shipping.
• Chabahar route: Ships can sail along Iran’s coast up to Chabahar Port, then head south into international waters before making a direct run to India’s western ports.

Under maritime law, the US cannot freely intercept ships inside another country’s territorial waters, limiting the effectiveness of its blockade.

Legal and strategic complexities

The United Nations Convention on the Law of the Sea allows “innocent passage” through territorial waters, meaning commercial vessels can transit peacefully without interference. In principle, this would allow Indian ships to pass through Pakistani waters.

However, strained relations between India and Pakistan complicate matters. Reciprocal maritime restrictions and political sensitivities make such routes risky, even if legally permissible.

A retired Indian Navy officer noted that most Indian-bound cargo travels on foreign-flagged vessels, and rising insurance costs and operational risks are already discouraging traffic. He added that the Indian Navy likely coordinates discreet escort operations, meeting ships in safer zones before guiding them toward Indian ports such as Mumbai or Kochi.

Limits of the blockade

While Donald Trump has described the blockade as a success, US forces have so far only redirected or detained a limited number of vessels. Once ships enter Iranian, Pakistani, or Indian territorial waters, they move beyond easy American reach.

Despite pressure on Iran’s oil exports, the continued movement of discounted crude highlights a key reality: in modern maritime trade, even powerful naval blockades are difficult to fully enforce.

With multiple routes still open — whether via Chabahar or along the Makran coast — the flow of oil from Iran to India remains viable, shaping both regional energy security and geopolitical calculations.