This article is from the 19th - I posted it on another thread. In the article, they describe some of the resources that the US Navy has for rescuing trapped submariners .....
From link:
On Saturday, the Undersea Rescue Comand, or URC, shipped out two “independent rescue assets” from San Diego en route to the Southern Atlantic, where the Argentine Navy lost communications with one of its submarines. They are expected to arrive on Sunday, officials said.
The highly trained American sailors will employ advanced technology on the Submarine Rescue Chamber, or SRC, which has already been in touch with the family members of the 44 on board, and will utilize an underwater system called Remotely Operated Vehicle, or ROV. It can climb down to depths of 850-feet and pull to safety “up to six persons at a time,” the Pentagon officials said.
The sailors will also be relying on Pressurized Rescue Module, or PRM, which can rescue “up to 16 personnel at a time ... by sealing over the submarine’s hatch allowing sailors to safely transfer to the recuse chamber,” according to officials.
The American reinforcements will join the Navy’s P-8A Poseidon multi-mission maritime aircraft and a NASA P-3 research aircraft that have been assisting the ongoing search for the ARA San Juan, a German-built TR 1700 class diesel-electric submarine.
Since the whole crew cannot be evacuated st once, I wonder if they would take air tanks with them to replenish the oxygen supply within the submarine as they bring personnel up to the surface.