HIGHLY-trained navy divers were today searching the hull of an upturned trawler off the Suffolk-Essex coast after two men died when the vessel capsized.

HIGHLY-trained navy divers were today searching the hull of an upturned trawler off the Suffolk-Essex coast after two men died when the vessel capsized.

Search and rescue teams found the bodies of two fishermen floating in the sea, but there was no sign of their two colleagues.

Coastguards said there was a "slim chance" that the men could still be alive but trapped inside the water-filled hull of the trawler which capsized within minutes in darkness on the North Sea, about 20 miles east of Felixstowe and Harwich.

The only hope was that the men – both Belgians – may have found an air pocket below decks to hide in and keep alive, waiting agonisingly to see if they will be found and rescued.

Thames Coastguard was alerted to the accident just after midnight after receiving a signal from an automatic satellite mayday system on the vessel Flamingo.

Devices on the trawler recognised that the boat was in trouble and beamed a distress mayday to a space satellite, but Coastguards said the capsize must have then happened so quickly as there was no time for the crew to add any details.

A major search and rescue operation was immediately launched, co-ordinated by the Thames Coastguard.

Harwich and Walton RNLI lifeboats were launched and a search and rescue helicopter from RAF Wattisham was also scrambled.

Pilot boats from Harwich and Felixstowe went to the scene, a Belgium helicopter was sent, and ships in the area were asked to help. Two of the first on the scene were a dredger Arco beck, and a trawler Aquarius, whose crew said the keel of the capsized boat was clearly visible.

The body of one fisherman was found close to the upturned hull of the 24ft Flamingo, which operates out of Zeebrugge, and the other about a mile away.

A Coastguard spokesman said a team of Royal Navy divers had been flown by helicopter from Portsmouth and landed on the Walton lifeboat at about 7.30am.

"The divers are highly-trained in this kind of mission and will be diving down and going up into the capsized vessel to search the hull," he said.

"There is a slim chance that the other two men are alive but at this stage we just don't know."

Diving was quicker than trying to cut through into the thick steel hull. The team would be making a thorough search below decks.

The reason why the accident happened is still a mystery, though a full investigation will take place. It is not known whether another vessel was involved, or if trawling nets became snagged on something below the waves.

Coastguards said the weather at the time was reasonable and conditions were good for fishing, with force two to three wind.

The Walton lifeboat crew was one of the first on the scene, using searchlights to sweep the area until daylight at around 5am.

Stewart Oxley of Walton Lifeboat said: "We found one body close to the upturned hull and a second body was found in the sea away from the vessel.

"The search is still ongoing by the crews of the lifeboat as two people are still unaccounted for."

To enable the search to continue unhindered today, a six-mile exclusion zone was placed around the trawler at sea and in the air.

Wattisham again sent a fresh crew out at 9am to make another search of the area in case the two missing men were not trapped inside the hull.