Seeking Somali pirates, from the air

From a desert airbase in the United Arab Emirates, a Royal Australian Air Force Orion surveillance plane taxis along the tarmac.

The 13-strong crew, part of a 25-nation coalition force, has been tasked to patrol two huge patches of ocean between the southern coast of Oman and the Horn of Africa.

It is where Somali pirates were last seen operating - and it is where they are thought to be lying in wait for their next victims.

Maritime piracy off the Somali coast is estimated to have cost the global shipping industry about $5.6bn (£3.6bn) last year alone and, along with the growing terrorist threat, it is one of the principal reasons David Cameron has convened this week's Somalia conference in London.

Over 100 seafarers and several ships are currently held for ransom in often atrocious conditions.

What started out a few years ago as a local vigilante reaction by Somali fishermen - fed up with foreign fishing fleets plundering their waters - has now evolved into a massive and sometimes murderous business.

Ransoms run into the millions of dollars, crews are sometimes tortured to put pressure on ship-owners to pay up, and ships have been attacked as far as 1,000 miles (1,600km) from Somalia.

Vast ocean

So how does patrolling the vast Indian Ocean by air make any difference?

It is a long sortie - ten hours in the air, banking and diving - down to the Horn of Africa and back.

Flying low, the Australians record every vessel in a designated search area.

The plane has an electronic optical (EO) camera beneath the nose, producing high-resolution photographs that can be beamed instantly back to analysts onshore in the UAE and Bahrain. Sitting just behind the pilot, a photographer uses a hand-held telephoto lens to take digital photos as back-up.

"Basically we are just seeing what sort of vessels are in the area," says aerial analyst Sergeant Scott Brando.

"We're looking for any acts of piracy. The radio operator puts through any surface contacts that the radar picks up, big or small."

The Australians spot two fishing boats tied together: it looks suspicious.

Something has gone overboard with a visible splash. Is it weapons?

The plane zooms in low to check. It turns out to be a person, falling in as he crossed from one boat to another. The Australians send the photos back for analysis anyway.

They have something called a Hisl (High Interest Shipping List) of vessels they believe have been taken over by pirates and which are now being used as "motherships" to launch attacks on unsuspecting shipping far out to sea.

If pirates are confirmed onboard, the nearest warship is scrambled to investigate.

But what happens behind the scenes when a ship is first approached by pirates?

Phone alert

The tranquil gardens of the British Embassy in Dubai seem an unlikely setting for a Royal Navy operations room. But this is the home of UK Maritime Trade Operations (UKMTO), the first point of contact for all merchant shipping transiting the high-risk area.

If a ship is under attack or getting approached by a suspicious craft then the crew call one of two mobile phones lying on the desk.

While we are there, a call comes in from a merchant vessel, very concerned about a fishing boat towing a "skiff," a slim, fast speedboat favoured by the pirates. This skiff contains five people with a rocket-propelled grenade and other weapons.

It is said to be moving aggressively towards the vessel and comes within 450m. But the crew have an armed security team onboard that fires warning shots, and the pirates withdraw, waiting for easier prey.

When a crew does get overrun by pirates, the operations room in Dubai takes some terrified calls. Leading Seaman Mark Ray is one of the watchkeepers.

"They're going to be in a massive panic. They are going to be running around the bridge. If they are getting shot at they are going to be hiding," he says.

"Sometimes they might be phoning from the citadel which is where they might have locked themselves into the ship."

'Land solution'

The number of successful pirate attacks is coming down. But the pirates are growing more violent and attacking ever further afield.

This tanker crossing the Somali basin was checked out

Commodore Simon Ancona is Deputy Commander of the Combined Maritime Force.

"If nothing else the pirates have proved how resilient they can be," he says.

"They are determined, they are flexible, innovative, they're conforming to a very lucrative business model.

"I think if I was a pirate I'd rather hope for complacency on the part of the international community because successful attacks have reduced."

Everyone agrees the solution to Somali maritime piracy is not at sea, it is on land - and that is largely what this week's conference will be trying to address.

But until that happens, Somalia's pirates will continue to risk capture, drowning and death for this multi-million pound business.