The Strait of Hormuz in 8 Charts

Access to the Strait of Hormuz, which carries roughly a quarter of global oil flows, remains contested. The waterway has been effectively closed since March 2, following U.S. and Israeli strikes on Iran. Although Tehran declared the strait open on April 17, the Islamic Revolutionary Guard Corps reversed course and announced it shut just one day later. The United States has since moved to enforce its own presence, including by seizing an Iranian-flagged cargo vessel on April 19. Vessel tracking and maritime trade data offer key insights into the ongoing dispute. 
 

1. Tankers Raced for the Strait, but Few Made It Through

Since the conflict in Iran began, hundreds of tankers have been stranded in the Persian Gulf. After Iran’s foreign minister announced the reopening on April 17, dozens of vessels surged toward the Strait of Hormuz, trying to exit. Automatic identification system (AIS) data from Starboard Maritime Intelligence shows that most quickly reversed course and remain stuck in the Persian Gulf, but at least 13 tankers made it through. 
 

2. Ship Traffic Remains at a Fraction of Prewar Levels

Daily transits of the strait remain well below pre-conflict levels. While some vessels may be operating “dark,” with AIS transponders switched off and therefore not captured in the data, commercial traffic through the strait largely has not recovered.
 

3. Transits Through Hormuz Concentrated Among a Small Set of Countries

Of the 187 vessels that have successfully transited the strait since March 4, over half are operated by shipping companies located in just four countries. China’s position at the top of that list is notable, given reports that Beijing has pressed Tehran to protect Chinese shipping. 
 

4. Vessel Traffic Is Shifting Toward Routes Closer to Iranian Waters

Commercial shipping passing through Hormuz appears increasingly subject to Iranian conditions. Reporting suggests that some vessels are coordinating through designated intermediaries, sharing detailed voyage information, and in some cases paying additional fees to transit. Ships are also increasingly moving along preapproved routes closer to Iranian waters. Since March 15, most observed transits have followed these patterns. 
 

5. Major Asian and Gulf Economies Have Billions at Stake

Most of the trade (by value) moving through Hormuz is tied to a handful of economies. Gulf exporters depend on Hormuz to move the bulk of their output, while major Asian economies rely on it for energy imports. Many of the most exposed countries are key U.S. security partners.  
 

6. Crisis Pushes Up Agricultural Commodity Prices 

The crisis is pushing up prices for commodities tied to Gulf exports. Crude oil and fertilizer prices have risen sharply, reflecting the region’s central role in global supply chains. Grain, by contrast, has not yet experienced comparable price spikes seen in recent shocks. Sustained increases in energy and fertilizer prices could affect global food production prices over time. Higher energy costs are already increasing food prices in some markets. 
 

7. The United States Is Relatively Insulated from Rising Natural Gas Prices 

Since the crisis began, natural gas prices in Europe and Asia have risen sharply and remain elevated, reflecting their exposure to the ongoing disruption of maritime trade in the Persian Gulf. The United States, by contrast, is buffered by abundant domestic production, keeping prices relatively steady and leaving it better insulated than many of its allies. 
 

8. The Strait of Hormuz Is Just One of Several Critical Chokepoints

The Strait of Hormuz carries a smaller share of total seaborne trade than some other major chokepoints, but it remains a key conduit for global energy flows. Traffic moving into and out of the Persian Gulf cannot easily reroute when disruptions occur, leaving hundreds of vessels and billions of dollars in goods stranded since the conflict began. The ongoing disruption underscores the importance of keeping critical maritime trade routes open and secure.