For years, the sons of the commander of the USS Grunion have searched for the sunken World War II submarine in which their father perished.

Now, Cmdr. Mannert L. Abele's family finally has closure, along with the relatives of the 69 other victims of the shipwreck.

This week, the United States Navy confirmed that a submerged vessel found last year off the Aleutian Islands is indeed the Grunion — nearly 65 years after the ship was lost at sea.

One of Abele's sons, John Abele — the founder of medical device company Boston Scientific — funded most of the search. Like many children of the World War II era, Abele and brothers Bruce and Brad grew up fatherless.

"Not having a father wasn't an unusual thing," John Abele said in an interview with FOXNews.com. "There was a war."

But it wasn't easy for his family, he said, especially his mom, because they had so few answers.

"What was difficult for my mother was that there was never any evidence of what happened," Abele said. "Mother never remarried because she thought my father would one day come home."

But he didn't come home, and the circumstances surrounding the sinking of his ship remain a mystery.

Click here for photos.

The submarine arrived in Hawaii's Pearl Harbor during World War II on June 20, 1942, under Cmdr. Abele's direction. The vessel's crew were hailed as heroes after rescuing 16 survivors from a U.S. boat torpedoed by the Germans.

Ten days of intensive training later, the Grunion left for the Aleutian Islands. While patrolling north of Kiska Island, a Japanese destroyer attacked the ship, which fought back. The submarine continued to monitor the seas off Kiska and defend itself, sinking a handful of enemy boats.

The Grunion glided through the depths of the ocean to meet other U.S. vessels approaching Kiska. For five days, the ships observed the flow of opposition vessels, and on the sixth day, they guarded the exits. Shortly after taking that position, the enemy attacked. The Grunion fired two torpedoes, but wasn't damaged.

Two days later, a transmission was sent from the Grunion to Dutch Harbor reporting heavy anti-submarine activity at the entrance to Kiska. The submarine was ordered to return, but never responded. On July 30, the USS Grunion disappeared from sight and records.

Anti-submarine attack data from Japan recorded no strike in the Aleutians at the time of the Grunion's disappearance.

The discovery of the Grunion is a tale of international cooperation, bringing together more than 1,000 volunteers from Australia to Israel, John Abele told FOXNews.com.

It was a long process in a rough patch of ocean, and there were times it seemed the wreck would never be found.

• Click here to read more about the search for the USS Grunion.

But in 2002, fragmented clues discovered online about the ship's possible location turned into conclusive evidence helping the Abele brothers pinpoint where it might be and motivating them to keep hunting.

Thanks to what John Abele calls the "exponential power of the Internet," the brothers met a Japanese World War II buff and interpreter who had translated an obscure magazine article about the exploits of a Japanese freight ship and its run-in with the Grunion.

In fact, it was the Japanese, ironically, who provided some of the greatest contributions to the quest to find the submarine, with many of Japan's national newspapers publishing stories about it, according to Abele.

The brothers hired a team of sonar experts in August 2006. They found something about a mile below the surface in the Bering Sea and, using a high-definition camera, got images of what turned out to be the sunken ship during a second expedition a year later.

Those underwater photographs and video footage allowed the Navy to confirm that the shipwreck was the lost sub, Rear Adm. Douglas McAneny said this week.

"We hope this announcement will help to give closure to the families of the 70 crewmen of Grunion," he said Thursday.

The search for the Grunion depended on worldwide collaboration, Abele said. He and his brothers have paid homage to the Japanese vessels sunk by the Grunion.

"We live in a global world," Abele told FOXNews.com. "It's a matter of respect for all of those folks, Japanese soldiers and U.S. soldiers, who fought like hell for their beliefs."

At long last, a chapter has been closed. Deep in the Bering Sea, a sub apparently sunk in battle was found again with international cooperation and an army of citizens.

For bringing once-warring people together, the USS Grunion is hero again.