CLARKSVILLE, Tenn. (AP) — Cpl. Edgar Harrell floated in the shark-infested Pacific Ocean for four-and-a-half days.

He swam aimlessly in the salt water — mixed heavily with black oil and blood — with a group of 80 other men who had jumped off the fiery USS Indianapolis after it has been torpedoed by the Japanese during the closing months of World War II.

It was July 30, 1945, and it was 110 degrees. They had no water. Dehydration left their lips covered with sores and their tongues swollen.

By the afternoon of the third day, the group dwindled to just 17 men. Shark fins and the torsos of those they had killed surrounded them. One would scream each time as they were pulled under, just for unrecognizable parts to bob back to the surface.

Harrell prayed continually.

Ultimately, Harrell was among the only 317 of the 1,196 men on board to survive, making the incident the single largest loss of life from a single ship in the U.S. Navy's history.

But there was no fanfare when the men returned from the Pacific as the U.S. government kept quiet about the Indianapolis until Aug. 15 in order to guarantee that the tragedy would be overshadowed by President Harry Truman's announcement that Japan had surrendered.

Harrell spent months in the hospital recovering from a perforated appendix. He thought of how he had been promoted to sergeant on the ship, but it hadn't been official. Documents were lost, along with the ship's wreckage. He hadn't been awarded the three chevrons indicating his new rank.

No matter, he had thought. Men had died and he had to tell their story.

Harrell, now 93 and living in Clarksville, sat inside Calvary Bible Church in Joelton on Thursday and thought of those men once again.

"I can't tell the story without reliving it somewhat," he said in an interview with USA TODAY NETWORK - Tennessee. "I'm an old man today, but the good Lord is still watching over me. I hope I have some more time to go and tell this story."

The church, where Harrell's son, David, is a pastor, was filled with his family and friends dressed for a special occasion. They had gathered for something that's been long overdue: Harrell's official promotion.

"We have a saying that once a Marine, always a Marine. We might be a little late with this one," Maj. Gen. Paul Kennedy said in the quick but emotional ceremony. "The Marines have been inspired by the legacy of (Harrell)."

And in a moment not too soon, the three chevrons were at last pinned to Harrell's jacket. The now sergeant turned to look at the group who stood and clapped for him.

"Stay faithful," he said simply, touching on his faith that he credits to have saved him at sea.

His "little" brother, Bill Harrell, who towers over Edgar Harrell's small frame, made his way to the front and embraced his brother.

"I'm so proud of you," he whispered. He was just as proud as he felt when his saw his brother return decades ago.

Then just 8-years-old, the younger Harrell sat with their father and mother as they listened to Gabriel Heatter, a radio news commentator famous for his uplifting broadcasts during the war, report that Indianapolis had sunk.

Soon after, they received a telegram that his brother was missing.

"We stayed glued to the radio for days to hear what had happened to Edgar. When we eventually found out he had survived, it was incredible," Bill Harrell told the USA TODAY NETWORK - Tennessee.

"To go through that and to see him standing here with this recognition is beyond words."

Harrell has written a book about his terrifying firsthand account of the Indianapolis. He's shared his story with anyone who asks, still continuing his promise to remember those who had died.

He became a celebrity of sorts last year when the ship's wreckage was finally located after seven decades of searching.

He answered as many calls and emails he could from those who wanted to hear about what had happened. His calendar filled up with stops in cities like Knoxville, Indianapolis and New Orleans.

It was in Salt Lake City where he met Capt. Scott Montefusco, the organizer of Utah Military History Group. After a two-day talk, Harrell joined the group to ride in the Veteran's Day Parade.

"That's when we were able to have personal conversations," Montefusco said Thursday. "And that's when I learned how this amazing man was never recognized for his sergeant rank."

Harrell didn't speak often of his "unofficial" rank. He considered it "more trouble than it's worth."

It only came up in their chat when Harrell wanted to tell Montefusco a funny story about how he had snuck out of his bed while on Indianapolis to sleep on the lifeboats to escape the unbearable summer heat below deck. It wasn't until he was promoted that he stopped because he didn't want to lose his rank, Montefusco said with a laugh.

"But the whole time I kept sitting there thinking that we needed to fix this," he said. And so he reached out to Sen. Bob Corker's office to get help.

And in what Kennedy described as the "fastest piece of legislation to be signed," Harrell's honorary promotion was approved with the signature of the Secretary of Defense, Secretary of the Navy, Corker and Commandant of the Marine Corps. Gen. Robert Neller, who couldn't make the event Thursday as he was overseas.

"I felt a sense of accomplishment to see this happen," Montefusco said. "(Harrell) has dedicated his life so that future generations don't forget about this tragedy."

The Indianapolis was sent on a mission so top secret that ship's crew was unaware of its cargo. They delivered the key components of the atomic bomb that would be dropped a week later on Hiroshima.

The ship was heading to Leyte Gulf in the Philippines to join the battleship USS Idaho to prepare for a possible invasion of Japan when it was struck twice by Japanese submarines.

Harrell was asleep when the second torpedo hit the middle of the ship, near the fuel tank. It was dark, the power knocked out by the explosion, but he could feel water flooding below deck. The only source of light was the fire.

Then he heard his captain from a far: "Abandon ship!"

Indianapolis sank in 12 minutes with about 300 men trapped inside. Harrell and another 900 men jumped into the water where many perished. Help didn't arrive for four days.

When help did come, Harrell was flown to a hospital on Guam. He was still there when the "Little Boy" was dropped on Hiroshima on Aug. 6, 1945. Nearly 130,000 people died and more than 60 percent of the city was destroyed.

Harrell said he believes that Truman made the right decision to drop the bombs in order to end the war.

"It was devastation to Japan but look at Japan now," he said. "They are our friends in the Pacific."

Harrell said recently, the great granddaughter of Commander Mochitsura Hashimoto came to visit him in Clarksville. Hashimoto had ordered the torpedoes that sank the Indianapolis. Days later, much of his family died in the Hiroshima bombing.

"That man sank us and now I know several of his family," Harrell said. "It's called reconciliation. The little girl to come and hug my neck, it was an honor."

"I wanted to take them out for supper and guess where they chose . Cracker Barrel," he said with a laugh.

Harrell called his promotion a "double honor" and something he didn't realize was in the works until he was asked Monday when he might be available.

"I'm just delighted and to see this turn out, I am very honored. It's an honor for me to live and tell of the tragedy that all of those 880 boys had to experience for the freedom America has today," he said.

Yihyun Jeong covers veterans and military affairs for the USA TODAY NETWORK - Tennessee. Reach her at yjeong@tennessean.com or 615-881-7309. Follow her on Twitter @yihyun_jeong.

___

Information from: The Tennessean, http://www.tennessean.com