On 2 April 2021, whilst U.S. Coast Guard patrol boats USCGC Wrangell and USCGC Monomoy were conducting maritime security patrols in the international waters of the southern Arabian Gulf, they were involved with Iran’s Islamic Revolutionary Guard Corps Navy (IRGCN) Harth 55 in what is being described as an ‘unsafe and unprofessional interaction’.
It has been reported by the U.S. Navy Office of Information that their crews issued bridge-to-bridge radio warnings and short blasts from the ships’ horns and, while the Harth 55 responded, the unsafe manoeuvres supposedly continued.
The actions of the IRGCN are said to have not been in accordance with the Convention on the International Regulations for Preventing Collisions at Sea or the internationally recognised maritime customs.
Following hours of warnings and manoeuvres – with the Harth 55 repeatedly crossing the bows of the U.S. patrol boats at close range – they moved away from the U.S. ships.
The USCGC ships are assigned to Patrol Forces Southwest Asia, the largest U.S. Coast Guard unit outside the United States.