From dailymail.co.uk:
American military chiefs have been left dumbstruck by an undetected Chinese submarine popping up at the heart of a recent Pacific exercise and close to the vast U.S.S. Kitty Hawk – a 1,000ft supercarrier with 4,500 personnel on board.
By the time it surfaced the 160ft Song Class diesel-electric attack submarine is understood to have sailed within viable range for launching torpedoes or missiles at the carrier.