| Date | 4 Jan 2021 |
| Tracker | Strait of Hormuz Tensions |
| Type | Interception |
| Location |
Strait of Hormuz
26.18, 56.25 (approximate) |
On January 4, 2021, Iran's IRGC Navy seized the South Korean-flagged chemical tanker Hankuk Chemi near the Strait of Hormuz, escorting it to Bandar Abbas. Iran's maritime authority alleged the vessel, carrying roughly 7,200 tons of ethanol and other chemicals, had repeatedly polluted Gulf waters; the tanker's South Korean operator denied any spill occurred. The seizure came as Seoul faced pressure from Tehran over roughly $7 billion in Iranian funds frozen in South Korean banks under US sanctions. The 20 crew members were held aboard. Iran released the tanker on April 9, 2021.
| Series | That day | Prior 30-day avg | Week after vs before |
|---|---|---|---|
| Transits | 51 -13% | 58.7 | -9% (452 → 410) |
| Tankers | 33 -12% | 37.3 | -9% (290 → 264) |
| Cargo ships | 18 -16% | 21.4 | -10% (162 → 146) |
| Date | Type | Incident |
|---|---|---|
| 19 Jul 2019 | Interception | Iran seizes British tanker Stena Impero in Strait of Hormuz, retaliating for Gibraltar's Grace 1 seizure |
| 30 Jul 2021 | Strike | Iranian drone attack on tanker Mercer Street off Oman kills two crew members |
| 3 Aug 2021 | Interception | Armed boarders briefly seize tanker Asphalt Princess off UAE in foiled hijacking |
| 27 May 2022 | Interception | Iran seizes two Greek-flagged tankers, Prudent Warrior and Delta Poseidon, in the Persian Gulf |
IMF PortWatch data published on GMN's Strait of Hormuz tracker shows commercial ship transits averaging 3.17 a day over 1-6 September 2026, against 85.5 a day in 2025; other counters read higher, but every independent count is a small fraction of the pre-war norm.
Iran's Revolutionary Guard said on 8 September 2026 it had recovered a US Navy Anduril Dive-LD autonomous underwater vehicle at the entrance to the Strait of Hormuz; US Central Command said the vehicle had malfunctioned more than a day earlier, and Anduril confirmed the loss.
The United States decommissioned its four Bahrain-based Avenger-class mine hunters in September 2025 and shipped the hulls home in January 2026. When Iran began mining the Strait of Hormuz two months later, according to CENTCOM, the Navy had to sail two of its last four minesweepers from Japan.