A Westcountry-based warship has put on a show of force to make pirates in one of the world's most dangerous maritime zones think twice before taking them on.
HMS Monmouth joined forces with a US warship for the excises in the Gulf designed which were also designed to show merchant vessels that they are safe to travel the notorious shipping lanes.
Commanding officer of the Plymouth-based ship, Commander Gordon Ruddock, said it had been a useful exercise.
"It will give confidence to the merchant marine community that we are ready, willing and able to protect them should they need us," he said.
"With fully-laden cargoes of over 150,000 tonnes, it is important that merchant ships such as these are able to transport their cargo around the world without fear of piracy or other attack."
The patrol is vital to UK and world trade as each day 17 million barrels of oil pass through the Strait of Hormuz, while 3-4 million barrels are moved through the Bab-al-Mandeb Strait, gateway to the Red Sea.
In a typical week, more than 500 ships pass through Hormuz – three in every five of them energy carriers with loads including liquefied natural gas which is used in the UK.
The exercise tested mock crisis centre staff in Bahrain, merchant sailors and the military response, should shipping come under terrorist attack.
HMS Monmouth, known as the Black Duke, was given the task of providing close protection to two huge tankers, including the Bahamian-registered Arcturus Voyager, an impressive vessel measuring 333meres in length and displacing 160,000 tonnes but which travels at only five knots.
The UK warship was supported by US Navy and coast guard patrol ships, a supply vessel and the air defence destroyer USS Winston S Churchill, which had a Royal Navy navigator aboard.
Lieutenant Chris Hollingworth, principal warfare officer in HMS Monmouth said: "It was great to be able to demonstrate to the tanker captains how we would be able to deal with threats and offer them a level of protection."
The ship, which has recently taken over from HMS Diamond, will return to Plymouth in the spring.