Vessel Seizure Tracker

The vessel seizure pattern during the Hormuz crisis follows a clear tit-for-tat escalation model. Iran's Islamic Revolutionary Guard Corps (IRGC) initiated seizures on March 20, 2026, targeting commercial vessels transiting international waters near the strait. The initial targets were Marshall Islands and Liberia-flagged tankers — vessels with minimal state backing that Iran assessed would not trigger a military response. The strategy was calibrated to raise pressure without crossing the threshold into overt warfare.

The US and UK responses came in April, with targeted detentions of Iranian-flagged cargo vessels. These retaliatory seizures were carefully chosen to demonstrate capability while maintaining proportionality. However, Iran's subsequent seizure of a UK-flagged tanker (MV Stena Impero II) and a Hong Kong-flagged container ship marked a significant escalation, broadening the scope beyond Gulf states to include NATO-aligned and Chinese-interest vessels. The seizure of an LNG carrier (MV Brave Explorer) in late April represented a new threshold, as LNG carriers are among the most valuable and strategically significant vessels in global trade, each carrying cargo worth $50-100 million.