The US Navy said in a statement that 11 Iranian Islamic Revolutionary Guard Corps Navy (IRGCN) vessels repeatedly conducted "dangerous and harassing" approaches of US Navy and Coast Guard ships conducting manoeuvres in international waters of the North Arabian Gulf on Wednesday, April 15.
The Iranian vessels had sailed dangerously close to the expeditionary sea base USS Lewis B. Puller, the guided missile destroyer USS Paul Hamilton, the patrol ships USS Firebolt and USS Sirocco, and the US Coast Guard cutters Wrangell and Maui while the American vessels were conducting joint integration operations with US Army AH-64E Apache attack helicopters in the gulf.
The IRGCN vessels repeatedly crossed the bows and sterns of the US vessels at extremely close range and high speeds, including multiple crossings of Lewis B. Puller with a 45-metre closest point of approach (CPA) and within only nine metres of Maui's bow.
The US crews issued multiple warnings via bridge-to-bridge radio plus five short blasts from the ships' horns and long-range acoustic noise maker devices but received no response from the IRGCN.
After approximately one hour, the IRGCN vessels responded to the bridge-to-bridge radio queries, then manoeuvred away from the US ships and opened distance between them.
The US Navy said that the IRGCN's dangerous and provocative actions increased the risk of miscalculation and collision, were not in accordance with the internationally recognized Convention on the International Regulations for Preventing Collisions at Sea (COLREGS) "rules of the road" or internationally recognised maritime customs, and were not in accordance with the obligation under international law to act with due regard for the safety of other vessels in the area.