I watched a "mudlarking" video which led me to a video of a guy scuba-diving a river with a metal detector, gathering items people had dropped and reuniting cell phones with their owners; this led me to a guy going along Daytona Beach in Florida, with a metal detector, which led me to a guy who'd bought a storage unit and was going through it with his dad.

The "mudlarking" guy found historical items
The scuba guy found cell phones, money and sunglasses
The Daytona guy found money and small metal items
The storage unit guy found money and jewelry and other valuable stuff

That's cool!!