Royal Navy minesweepers patrol the Gulf

Image caption HMS Pembroke's duties see it patrolling throughout the Gulf

Away from the headlines, the Royal Navy is carrying out a key security task in the Gulf.

For the last few years, four small UK minehunters have been maintaining a valuable if unsung presence in the waterway. It is one that Britain's allies value very highly, according to the Navy.

We joined one of the ships, HMS Middleton, as she headed out to sea from her base in the port of Bahrain. As we set sail, the international significance of the Gulf was evident.

As well as the four British minehunters, a frigate and a patrol craft from the Bahraini navy, dotted around the port were a French naval support ship, a US amphibious assault ship, some American minehunters and perhaps most intriguingly, a US Coastguard cutter.

There was also a huge British amphibious support ship, the Royal Fleet Auxiliary Lyme Bay, another of the total of a dozen British naval vessels in the region. Lyme Bay acts as a mother ship for the minehunters.

Those minehunters themselves are hardly the biggest or most glamorous of warships. HMS Middleton is just 645 tons, with a crew of just 46. But their potential value massively outweighs their size.

If the Gulf were to be mined, the bigger ships - even the mighty US Navy aircraft carriers - would be relying on them to carry out their task.

None of the Royal Navy personnel in the Gulf will point a direct finger, but one of the West's nightmare scenarios is that the Gulf could be mined as part of a confrontation with Iran.

That could shut off the source of 40% of the world's oil shipments by sea and have a devastating effect on the world economy.

The waterway has been mined before. And in both the recent confrontations with Iraq, Royal Navy vessels have played a crucial role in mine clearance.

Mines could also be attractive to a terrorist group. Like their land equivalent the roadside bomb, they are simple, cheap, but devastating.

Image caption HMS Chiddingfold leads her fellow minesweepers out of Bahrain on a joint exercise

The purpose of the ships now is to build confidence. And they are also there to gain vital local knowledge so that they could respond immediately if the need arose.

"We're the core of a deployed force which proves that the UK can deploy and sustain a force in theatre," according to Lt Cdr Phil Dennis, HMS Middleton's commanding officer for the last few months.

One of HMS Middleton's "secret" weapons is a remote mini-sub called the Seafox - in effect, an underwater "drone" - which the crew can deploy from the ship to investigate and if necessary destroy suspected mines.

This is one area where the British military believes it has some of the best equipment in the world.

And that is one reason why the British minehunting commitment is especially valued, according to the senior UK naval officer in the Gulf, Commodore Tim Fraser.

"The UK has for many years had a very good capability, one of the world leaders, and we work very hard to maintain that at that level," he says.

The Gulf is an especially difficult environment. And, with summer temperatures of 50C, it is hard work for the crews and the ships, which were really designed for the North Sea.

"If we can conduct mine-countermeasures operations in the Gulf, we can probably do them pretty much anywhere," says Lt Cdr Dennis.

The minehunter force, like the rest of the Navy, is spread pretty thinly. So, in a novel approach, to maintain a four-vessel commitment in the Gulf, the Navy keeps the ships stationed there for years and rotates the crews every six months or so, rather than have the ships themselves ply back and forth to the UK.

The waters may seem relatively calm at the moment. The Royal Navy believes its long-term presence and that of other international navies has helped maintain that stability, although elements in Iran - just across the water - clearly take exception to it.

The Navy has more reason than most to recall that Gulf waters can be treacherous - after the capture by Iran of 15 personnel from the frigate HMS Cornwall.

The Gulf is not Afghanistan. But when HMS Middleton put to sea, she was accompanied by a US Navy patrol craft "riding shotgun". And members of her crew in camouflage manned rapid-fire guns dotted around the ship.

Image caption The ships are deployed to protect UK interests in the Gulf, and those of its allies

"Your lookout has to be up all the time", says the navigating officer, Sub Lt Matt Millyard. "In the UK, you wouldn't be worried about a fisherman coming up very close to you. But here, if a fisherman comes close to you, you have to be very wary and watch them."

In the wider region, there is the threat of piracy. And the apparent attack on a tanker in the Straits of Hormuz by a boat laden with explosives last summer, raised another set of alarms.

"We have combined maritime forces in this region, 25 nations working together on counter-piracy and counter-terrorism," says Commodore Fraser.

On the failed tanker attack, he says: "It's a reminder to be very vigilant, very aware, and for these maritime forces to continue to be ready to disrupt and deter."

Afghanistan remains the UK military's main focus. But HMS Middleton and the other Royal Navy vessels in the region are likely to be maintaining a presence for a considerable time to come.

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