The Mansal 18, a purpose built survey ship hired by the British government, arrived above the wreck, in the Barents Sea 70 miles north of Norway's North Cape, on Sunday night. The Mansal's crew used the submarines, fitted with video cameras, to relay pictures back to the survey ship. The investigators hope they will provide vital clues to the sinking.
Relatives of some of the 36 fishermen who died in the tragedy were watching when the first pictures were received.
Aubrey Bowles, whose 22-year-old brother Ronald was lost with the Gaul, said: "At the beginning it was with trepidation that we came here, but now that we are here and we have identified the wreck, it is with a bit of satisfaction that we are now maybe getting close to the truth of what really happened 24 years ago.
"At the moment, we are just doing a debris search around the vessel before we actually go in for close contact."
Marine Accident Investigation Board spokesman David Stewart said: "One remote operated vehicle (ROV) has been sent down with cameras on board and has sent pictures back up to the ship.
"You can see lifeboats there, and we have clearly seen the word `Gaul' written on the side of the boat. Weather conditions are good and the sea is calm, and the team are working 24 hours a day to get as much information as they can before returning."
The Gaul had been partly covered by fishing nets. "The nets have now been lifted by the ROVs and the ROVs are continuing to manoeuvre around the boat. We have to be very careful because earlier today one of them snagged on the nets," said Mr Stewart.
The Gaul is lying on its hull on the seabed some 300 metres down. There are no signs of an explosion, nor are there any signs of compression, which indicates that ship sunk slowly.
It is this lack of damage and the fact that none of the ship's distress systems were set off that is puzzling the investigators. If the ship sank slowly why did the crew not send a Mayday message? That has led families of the victims to suspect that the crew was taken by the Soviets and the ship then scuttled. One of the major concerns of the families is to establish whether there are any remains of bodies on the wreck.
Mr Bowles, 53, from Wallsend, Tyneside, said that he hoped the ROVs would enter the ship and film the bodies of his brother and other crewmen.
The Russians deny sinking the ship or any involvement and have helped recent TV investigations. However the Soviets are known to have seized British trawlers. In the 1950s the trawler Arnold Bennett disappeared and funeral services were held. Twenty-three days after it vanished the crew re-established radio contact, having been released from custody by the Soviets.
Evidence has grown of the involvement of Hull trawlers in secret intelligence operations against the Soviet Navy's northern fleet. Last year the Ministry of Defence finally admitted that Hull trawlers were hired to conduct such missions, but insisted that these operations stopped in 1973, a year before the sinking. It has now emerged that trawlers sometimes carried naval intelligence or GCHQ officers.
Last week Hull skipper Jack Lilley said that Peter Nellist, later skipper of the Gaul, helped him take photographs of a Soviet naval port for British Intelligence.
Another member of the Gaul's crew, Maurice Spurgeon, had also been involved in intelligence operations when he was mate of the Hull fishing vessel Invincible, which worked for the MOD. Roy Waller, the Invincible's skipper, said that Mr Spurgeon collaborated closely with the naval intelligence officer in charge.
For many years the British Government resisted pressure from the families to examine the ship, saying it would be too expensive to find. As recently as 1996 it said: "Because of the limited information about the Gaul's position when she went down it would be necessary to search hundreds, probably thousands of square miles of sea bed."
In 1997 Channel Four's Dispatches team hired a salvage ship and located the wreck.
The programme also revealed that several bodies were washed up on the Soviet coast after the Gaul was lost. Most of the Gaul's crew would have been below because of the poor weather conditions, but the men in the bridge could have been washed overboard.
Three bodies were washed up on the Rybachy Peninsula of northern Russia in April 1974 and were found by Soviet border guards. They were later interred in municipal cemeteries. One body was buried at a small, bleak cemetery outside the town of Nikel, marked by a small stone cairn and wooden cross.
A few days later a third body floated ashore, tattooed with English words. The body was taken away but its burial place is unknown - the records have disappeared from Soviet archives.Reuse content