I don't know if this is common knowledge or not, but I find it interesting.
When the Thresher sank, the Navy has everything that would float out searching for it. The fact that a fucking nuclear submarine was missing was kept under wraps, but the local press knew SOMETHING big was going on.
The way the story broke to the public was that a reporter who was ex-Navy parked his car on a pier, put his coat over one headlight and used his hat to flash out Morse code to the Navy ships passing by on the way to and from the search area. The people on this ships, assuming he was signaling from another ship, replied to his flashed messages.
I can't find the reporter's name online in a quick search, at lunchtime I'll have to look it up on my bookshelves upstairs.