Divers plunged to the bottom of the Barents sea today, beginning the long-awaited operation to raise the sunken submarine Kurskfrom the sea floor, the Russian navy said.
The first group of divers were lowered in a diving bell to the wreck to stencil holes that will be cut into the submarine's hull, navy spokesman Mr Igor Dygalo said in a statement.
A second group went down with cutting equipment and a third was to follow to begin actual cutting.
Divers recovered 12 bodies from the wreck last year, 100 metres below the Barents Sea north of Russia's port of Murmansk, before Arctic winter forced them to halt salvage operations.
Russian President Mr Vladimir Putin has vowed to raise the sub, both to recover the bodies of the crew and to dispose of its nuclear reactors. Some environmentalists say they believe burying the reactors under concrete on the sea floor would be safer.
The Barents Sea is one of the world's most important fisheries, and any leak of radiation could be devastating. No such leaks have been reported. The plan to raise the Kurskcalls for its damaged torpedo bay to be sawn off and abandoned on the sea floor for the time being. Holes will be drilled into the rest of the hull and cables fastened, lashing the submarine to a giant floating pontoon.
The 18,000 tonne submarine will then be hoisted to the surface and towed into port. Plans call for the operation to be complete by late September, before winter returns.
Russia has contracted with the Dutch salvage firm Mammoet and the Rotterdam-based marine services firm Smit International to raise the Kursk.
But many of the divers working on the salvage operation are Russians and Moscow says only they will be permitted to carry out work on sensitive parts of the sub.