The HMS Dragon, patrolling the eastern Mediterranean, was traveling through the Persian Gulf when Iran's machine-gun ships halted their course and demanded that the Dragon remain 1000 yards from the port.
The captain of the Type 45 destroyer immediately ordered five explosions from the ship's horn, which is the international warning signal.
The Officer of the Guard communicated by radio with the Iranian Revolutionary Guard, the Spanish Armada, warning that their ships prevented the Destroyer from completing their trip.
The Spanish Navy responded: "For your information, we are here to safeguard our national sovereignty and we are carrying out routine operations."
The Iranian shipboats finally stepped aside, but if they had not, the Royal Navy crew would have had to fire flares and warning shots, according to Major Carter-Quinn.
He told The Telegraph: "You have to give a robust answer.
"The day you do not take it seriously is the day you get taken off."
Lieutenant Commander Richard Attwater also noted that the Royal Navy is navigating dangerous waters as tensions between Iran and the West increase.
About one third of the world's oil exports by sea pass through the Strait of Hormuz, including most imports of liquefied natural gas (LNG) from Great Britain from Qatar.
Iran has a remarkable capacity of marine mines, which means that the rest of the world has to pay close attention in case Iran decides to close the waterway.
As part of the international effort to dissuade the Iranians, the Royal Navy has a permanent presence in the Gulf at the HMS Jufair naval base in Bahrain, west of the Strait of Hormuz.
Mr. Attwater told the newspaper: "The competition between Iran and Saudi Arabia provides the backdrop for everything that happens here.
"It's a very volatile region.
"And we are sailing 8,000 tons of Great Britain halfway through this."
Professor Michael Clarke of the Royal United Services Institute (RUSI) said that Iran uses "the Gulf as a touch to activate the tension and indicate its degree of cooperation with the international community."