MYSTIC, Conn. - The Submarine Service is often called the Silent Service.
While one aspect of that name derives from a submarine's stealth, another results from the fact that once a submarine submerges, much of what the ship and crew do is a mystery to those without an appropriate security clearance and need to know. John and Bruce Abele have had a need to know since World War II.
WWII sub mystery
Abele brothers discuss Grunion search, discovery.
Rest of story here.