– Famed oceanographer Robert Ballard discovered the Titanic, the Bismarck, the USS Yorktown and John F. Kennedy's PT-109.

This week, he added another accomplishment to his list of documenting the world's greatest shipwrecks: the first images in more than six decades of the USS Independence, an iconic World War II aircraft carrier scuttled in 1951 off the California coast, half a mile under the sea.

In a 20-hour-long expedition, Ballard's team, working with officials from the Navy and NOAA — the National Oceanic and Atmospheric Administration — revealed breathtaking images of the lost carrier's flight deck, a Hellcat fighter plane, anti-aircraft guns, hatches, ladders and even the letters of the ship's name still visible on the hull, all submerged 30 miles west of Half Moon Bay. Thousands of viewers in more than 30 countries watched the discoveries live over the internet. "What's so wonderful about the wrecks in deeper water, like this ship, the Titanic and the Bismarck, is that they are in amazing states of preservation," Ballard said.

"There's very little change from when the Navy scuttled it," he said. "The deep sea is the largest museum on Earth."

Ballard, a retired Navy officer, and his organization, the Ocean Exploration Trust, based in Connecticut, plan to build a detailed 3-D digital image of the Independence from photographs they took with two unmanned submersibles. "It was really nice to read the name on the side," he joked. "You think, 'Good, I found the right ship.' "

For hours as the images streamed in at nautiluslive.org, the adventure riveted viewers who were discovering the fate of the ship, not seen in 65 years, at the same moments as the 31 researchers aboard the Nautilus, Ballard's ship.

"We're pleased and surprised," said James Delgado, director of maritime heritage for NOAA, and lead scientist on the mission. "Independence is in much better condition than I had expected. It looks as it did in the 1946 photographs. It is a frozen moment in time."

Delgado said the discovery of a Grumman Hellcat fighter plane was among the most significant findings.

"It's damaged, but the star, the insignia, is still there on the wing and the 50-caliber guns are still in place," he said.

The Independence saw combat at Wake Island, Okinawa, and Leyte Gulf from 1943 to 1945, and was present a year later at the U.S. atomic tests at Bikini Atoll in the South Pacific. There, as part of nuclear tests, it was placed roughly 500 yards from two nuclear blasts so Naval officials could study their fleet's vulnerability. While the Independence sustained major damage in the atomic blast, it did not sink.

Then to dispose of it, Naval officials towed it out to sea, placed two torpedoes in the ship, and detonated them, sinking the ship on Jan. 26, 1951.