Iran has asked the International Maritime Organization (IMO) to act on alleged US misuse of VHF Channel 16, saying prolonged military broadcasts in the Persian Gulf threatened seafarers and interfered with safety communications.
Shipping Telegraph reported that Iran’s permanent representative submitted the allegations in a letter dated 9 October 2026. Tehran requested action by the relevant IMO bodies and distribution of the complaint to member governments, intergovernmental organisations and non-governmental organisations holding consultative status with the agency.
Iran said reports from vessels and shipping operators described US military transmissions in Persian that threatened and insulted Iranian crews. Some broadcasts urged seafarers to leave their ships, according to the complaint. Tehran argued that the lengthy transmissions placed crews under psychological pressure and risked delaying emergency messages.
The letter also alleged breaches of SOLAS requirements. Iran maintained that neither armed conflict nor a naval blockade justified using a maritime safety frequency to intimidate civilian crews. Shipping Telegraph said in its 14 October report that the US government had not officially responded to the allegations.
Iran cited IMO resolution A.954(23), which sets out guidelines for VHF use at sea. The guidelines discourage unnecessary transmissions and abusive language. They allow Channel 16 to carry distress and urgency traffic, short safety messages and initial calls, with subsequent exchanges moved to an appropriate working channel.
The complaint comes during US enforcement of a blockade on ships entering or leaving Iranian ports. A CENTCOM release dated 10 October, reproduced by Iran Watch, said enforcement had resumed on 14 July. The command reported redirecting 135 ships and disabling four merchant vessels. It also said US forces had destroyed 10 tankers linked to the Islamic Revolutionary Guard Corps.
CENTCOM said a US aircraft disabled the propulsion of the Panama-flagged Ocean Molica, also known as Arika Sun, in the Gulf of Oman on 10 October. It accused the vessel of attempting to breach the blockade after leaving an Iranian port and said the crew suffered no harm.
The IMO’s regional incident register listed 106 confirmed incidents and 24 seafarer deaths as of 13 October. Among the October cases, it recorded two crew members missing from Petro Dolphin and 12 injured aboard On Peace.
