The Russian Red Banner Fleet is rediscovering very deep manned salvage/rescue ops via atmospheric diving suits (ADS). These things date back to the 1900s with the U.S., Germany and the Brits leading the way and Moscow playing catchup. Since 1989, with the atrophy of the late-Soviet fleet, the Russians have largely lost their very deep skills and their divers have been kept north of the 100m depth with the only occasional use of hardhat gear on mixed air such as Heliox and Trimix to go gradually deeper.
However, over the past couple of years, the Russians have invested in relearning the lost skillset and last year used ADS systems to hit the 317m mark, and are pushing to 400m in coming months. More from Russian state media below:
Besides obvious overt uses in salvage and submarine rescues, such deep water skills also prove useful in covert taskings such as in eavesdropping on subsea cables.
As a matter of record, U.S. Navy Chief Diver (DSW/SS) Daniel P. Jackson hit the 610m mark inside a Hardsuit 2000 off southern California back in 2006. He reportedly enjoyed the show very much.
“At 2,000 feet, I had topside turn off all the lights, and it was like a star show. The phosphorescence that was naturally in the water and in most of the sea life down there started to glow,” Jackson said. “When I started to travel back up, all the lights looked like a shower of stars going down as I was coming up. It was the best ride in the world.”
In other news, Russian state media also posted this interesting piece about combat swimmers under ice. Seems like a theme.