The U.S.S. Grunion was lost on July 30, 1942 off Kiska Island in the Aleutian chain off Alaska. The captain’s three sons did not know exactly when, where or how their father’s boat was lost and set about finding out over many decades. Clues finally surfaced from slim accounts from survivors of a Japanese freighter, which was attacked in that period at that location. The sons eventually commissioned & organized two deep diving remote expeditions, which found the lost submarine at 3000 feet from which the cause of the loss was theorized. That cause may be the most interesting part of the story, although the determination of the son’s journey of discovery is vital.

https://www.legion.org/library/9370/...ry-solved-last

A video featuring one of the sons and exceptionally clear video is interesting —

https://youtu.be/JL9XAf_xAXE

3D Video of the separated bow section, which was found later —

https://youtu.be/0C3mjTHsErQ