Submarine crews practice surfacing the 8, 000-ton submarines, directly through thick ice or in nearby open waters, and learn to avoid hitting another ship.
FORBES: U.S. Navy Scrambles for Piece of Arctic Pie
2.
And there was the 2001 downing of a Navy EP-3 and the surfacing of a Song-class attack submarine in the middle of the Kitty Hawk strike group near Okinawa in 2006.