BRITISH relief teams stood by to help rescue the wrecked Titan last night – but experts warned the outlook was bleak.
The tourist deep-sea submarine disappeared in 3,800m of water – almost four times deeper than the maximum depth of NATO’s submarine rescue system, based at HMNB Clyde in Faslane.
Former Royal Navy submarine captain Ryan Ramsay said: “The chances of surviving are very slim. This depth is huge.
“Either something happened that left them stranded down there.
“In that case, they will quickly run out of air. Or they were crushed.
“At best they can conserve their air and pinpoint their position.
“It’s going to be really difficult to get anything there fast enough to help.
“There is no emergency vehicle that can get there to take people away.
“The only thing it could reach would be another special deep-sea submersible, but it wouldn’t be able to take people with it.”
Most of the world’s military submarines operate about 200 m below the water’s surface.
NATO’s submarine rescue system has a maximum depth of 1000m and the US Navy has similar equipment.
Operated jointly by the UK, France and Norway, the rescue units are designed to fit on aircraft and operate 24/7 anywhere in the world.
It includes a remote-controlled vehicle that can dive to depths of around 1,000 meters and provide emergency life support to a distressed submarine.
A larger, free-floating submarine rescue vehicle can only reach 610 meters.
Most submarines have a standard sized escape hatch to which the rescue vehicle can be attached to carry up to 72 passengers under pressure to the surface.
A Defense Ministry spokesman said: “As the host country of NATO’s multinational submarine rescue capability, we continue to monitor the North Atlantic incident and will lead and assist in any response measures as appropriate.”
Initial reports indicate that the tourist submarine disappeared in water much deeper than the rescue submarines could operate.