This was decided during a meeting of the WOAC committee, comprised of Trade Unions Nautilus International and RMT, and the UK Chamber of Shipping, on July 29.

The temporary agreement applies to all vessels entered into the UK Chamber and the clauses are invoked if flag state and industry guidance is not complied with.

That includes UK flagged vessels that refuse a military accompanied transit and vessels that do not take account of relevant guidance from industry bodies such as OCIMF, INTERTANKO, BIMCO and ICS.

The agreement gives seafarers the right to refuse to work onboard vessels transiting the Strait of Hormuz. Crew can request to leave the ship at a preceding port, for example.

...Nautilus International explained.

Seafarers on vessels transiting the area could also receive double basic pay from August 2, in recognition of the higher risks associated with transiting and operating in the zone.

Double basic pay would apply to each day the ship is in the specified zone. The payments are in addition to all other remuneration earned.

The agreement will cover the sea area as per the UK Government definition of the territorial limits of the Strait of Hormuz:

On the West: A line joining Ra's-e Dastakan (26°33'N – 55°17'E) in Iran, southward to Jaztal Hamra lighthouse (25°44'N – 55°48'E), in the United Arab Emirates (the common limit with the Persian Gulf).

On the East: A line joining Ra's Līmah (25°57'N – 56°28'E), in Oman, eastward to Ra's al Kūh (25°48'N – 57°18'E), in Iran (the common limit with the Arabian Sea).

The designation will be reviewed on September 2 or earlier if advice from the British Government changes.

The UK Department for Transport raised the Ship Security Level to 3 in July following several attacks on tankers in the Strait of Hormuz and the seizure of UK flagged Stena Impero, which remains offshore Iran with 23 seafarers onboard.

Reports say that Iran seized another a foreign oil tanker in the Gulf on 5 August, over fuel smuggling allegations.