(CNN) The USS Grunion went missing about a month after it departed on its first war patrol in 1942. It wasn't seen again until the sons of the Grunion's commanding officer began searching for it and found the wreckage in 2007 off the coast of the Aleutian Islands.
Now the submarine's bow has also been identified, about a quarter mile from the main wreckage, according to Tim Taylor of the Lost 52 Project, which searches for sunken World War II submarines.
In October 2018, the Lost 52 Project team returned to the site of the main wreck and found that the ship's bow had slid down a steep volcanic embankment, Taylor said.
They put together a 3D scan of the bow and presented it to the family of USS Grunion's Commanding Officer Lt. Cmdr. Mannert L. Abele.
"When we brought it back to the family, it opened up so much more understanding of what happened and why it sank and what happened to the submarine," Taylor said.
The USS Grunion was reported lost on August 16, 1942, after it fired on an enemy destroyer, sank three destroyer-type vessels and attacked enemy ships during its first war patrol, the US Navy said.
In 2002, Abele's three sons -- Bruce, Brad and John -- set out to pinpoint the Grunion's location after discovering a potential lead online, according to the US Navy.
They hired a team of side scan sonar experts in 2006 to locate a target almost a mile below the ocean's surface, the Navy said. In August 2007, they photographed the wreckage of the ship.
The vessel rests at about 3,200 feet underwater. Cold temperatures and lack of significant currents have preserved most of the ship.
The Navy says 52 US Pacific Fleet submarines were lost during World War II, and more than 3,500 submariners remain on "eternal patrol."