YOKOSUKA, Japan (AP) — When the submarine USS Ohio surfaced at sea and Machinist Mate 1st Class Jason Witty emerged from the hatch to look around, he saw calm, blue water under a peaceful sky — perfect for the solemn task he was about to perform.

On the map, the Ohio was afloat in just another indistinguishable expanse of the Pacific Ocean. As Witty stood on deck holding a silver pitcher, the vessel was alone.

Just like the ill-fated USS Indianapolis, 63 years earlier.

The pitcher contained the ashes of Witty's grandfather, Boatswain Mate 2nd Class Eugene Morgan, who had survived the sinking of the Indianapolis — one of the worst tragedies for the US Navy in the Second World War.

Morgan had died of a heart attack in June at age 87, just before Witty went to sea, and among his last wishes was the desire to be rejoined with his shipmates at roughly the same spot in the Pacific where the Indianapolis went down.

Witty, sitting in a wardroom of the Ohio at this Japanese port, recounted the October 2 burial at sea, saying he had never participated in one before.

He had sheepishly asked one of the officers if his grandfather's wish could be granted.

The request went up the chain of command to Capt. Dennis Carpenter, who quickly approved.

"I thought it would be an honour," Carpenter said. "And I wanted to make sure that we did it right. Sometimes on a submarine at sea, you just can't go topside. But everything seemed to be on our side."

In July 1945, the Indianapolis had just completed a secret mission to the tiny island of Tinian, carrying components for a new weapon — the atomic bomb. It would later be dropped on Hiroshima, Japan, in the world's first nuclear attack.

Because of its cargo, the Indianapolis had sailed to Tinian unescorted.

Now, with that mission done, the cruiser was making its way back to Leyte, in the Philippines, with a crew of 1,196 aboard, including Eugene Morgan.

Early on July 30, when the ship was still near the Marianas Islands, a Japanese I-58 submarine found the Indianapolis and launched six torpedoes, two ripping through its starboard side.

It took only 12 minutes for the Indianapolis to sink in the deadliest disaster at sea in US naval history.

Morgan was asleep when the ship exploded into chaos.

"He was in his skivvies," Witty said. "He was tossed from his rack. There were fires. He got topside and the boat started to capsize."

Morgan jumped off the port side of the ship and slid down into the black sea.

"At some point, he found some food floating on the surface and swam toward it," Witty said. "But on the way, he was attacked by a shark."

It swam away before going in for the kill. For the rest of his life, Morgan carried scars on his backside from the attack.

Many of his shipmates weren't so fortunate. Morgan could hear their screams as they were attacked.

By the time help arrived five days later, 879 sailors were dead — from drowning, sharks, dehydration, or from injuries suffered in the attack itself.

Morgan was one of only 317 to survive, floating on makeshift rafts, wreckage or clinging to each other.

The tragedy inspired the famous monologue in the movie "Jaws," in which the seasoned shark hunter played by Robert Shaw tells of the horrors of floating in the shark-infested waters while awaiting rescue.

Morgan was eventually saved when Navy seaplanes landed in the water and started to pluck out survivors. Some were hallucinating — they thought they were under attack by the Japanese again — and others were hysterical. Ships also arrived to assist in the rescue.

Only one more US ship would be sunk before Japan's surrender in August 1945. The Indianapolis itself has never been found.

Morgan, a Seattle firefighter after the war, kept the experience to himself for more than four decades.

Witty, of Puyallup, Washington, joined the Navy right out of high school. Two years later, his grandfather opened up.

"I knew that he was in the war, in the Navy, but he never really talked about it until after my grandmother died," Witty said. "One day I just got up the courage, and he told me the story."

Once the door was open, Morgan began talking about the tragedy every chance he got.

He was a frequent visitor at local schools and historical groups and took part in documentaries to make sure that the story of the Indianapolis would not be forgotten.

"I was worried that he would have bad feelings for me, being a submariner," Witty said. "It was a sub that sank his ship. But he never held that against me."

Morgan's burial at sea, on October 2, was simple but sombre.

Scripture was read, along with a eulogy written by another of Morgan's grandsons, Steven Wilson.

The order was given for the firing detail to ready their rifles, and three shots rang out.

Turning to face the sea, Witty held the silver pitcher wrapped in a blue cloth over the side of the deck and spread the ashes to the wind.

"Just going to that spot on the chart, what went through my mind was what they must have gone through," Witty recalled. "They knew they were by themselves."