"This astronaut found sunken treasure from space and kept it secret until his deathbed"

Vice:

Original Mercury 7 astronaut Gordon Cooper was supposed to be looking for nuclear launch sites on his record-breaking Faith 9 flight in 1963. He did his duty over the course of those 22 revolutions around the earth, clicking away on a camera that kept getting loose in zero gravity, barely able to move for 34 hours.

But he also kept getting anomalous readings from his equipment, pinging him for objects that were definitely not nuclear sites. The keen-eyed astronaut couldn’t help but put two and two together: metallic hulks beneath the sea, along the same routes used by Spanish traders? It had to be sunken treasure.

...

Cooper kept his secret for 40 years. Just before his death in 2004, he shared it with professional treasure hunter Darrell Miklos.