In fiction, it's common to see people on beaches looking around for stuff.
It happens in Real Life, too.
In Great Britain, they usually use metal detectors. This often carries the stereotype (in Britain at least) of someone who searches the countryside hoping to find buried treasure (not as silly as it sounds, since hauls of artifacts made of precious metals are occasionally found in Britain, which is what leads to this kind of behaviour in the first place). It's technically legal (and landowners have a good incentive, since they're entitled to a share of whatever's found on their land) and there are even specific laws for finding buried treasure (technically it belongs to the crown, but the finder and landowner will be paid a fee from whatever museum that ends up taking it), however for obvious reasons it greatly annoys actual historians and archaeologists, who'd rather see the sites properly excavated rather than plundered. This trope is not limited to beaches. See also Metal Detector Puzzle when this occurs in Video Games. Occasionally seen in Beach Episodes.
In Canada, the stuff that people look for is much more obvious and not buried in the sand. The long running TV series, Beachcombers had the starring character, Nick, making a living salvaging lumber, using his boat to haul lost logs into the water for towing to timber companies looking to recover their lost materials.
- Parodied in Spaceballs
Col. Sandurz: Are we being too literal?
We ain't found shit!
- In one episode of The Adventures of Pete and Pete, Dad explains that he met Mom when he was beach-combing and his detector went off at the metal plate in her head. In the same episode he tells this story, he's still combing the beach looking for something else really good... and finds an Oldsmobile Cutlass Supreme! He and his family dig it out of the sand and drive home in it.
- Heartbeat: Claude Greengrass finds some Roman coins in a garden of a Big Fancy House he'd been hired to look after. He spends a fortune on a dredger in an effort to find the rest of them, only to discover them just as the owner arrive home to claim the lot.
- As mentioned in the trope description, this was the backstory and occasional plot-starter in Beachcombers.
- The fourth case of the first Ace Attorney game has Phoenix use (and carry around) a metal detector lent to him by Detective Gumshoe. First he uses it to find a clue, at the end of the trial he uses it to prove that Von Karma has a bullet in his shoulder from when he murdered Edgeworth's father.
- In the Australia stage of Tony Hawk's Underground 2, there is a guy at the beach with a metal detector. From what he tells you when you talk to him, he's having no luck with his beachcombing. So, it's up to you to help him, by picking up cans from trashcans and giving them to him.
- In the Futurama episode "When Aliens Attack", Hermes is seen combing the beach with a metal detector. It turns out that he was using it to play hide and seek with Bender though.
- On King of the Hill, Peggy and Bobby engage in some beachcombing when vacationing on the shore, and coming in conflict with local beachcombers who don't appreciate tourists horning in on their turf.
- A recent[when?] example is this guy, who found the single largest stash of Roman coins in Britain.
- Similarly, a woman was prosecuted under the Treasure Act (which deals with finding and compensating artifacts with historical value) after failing to turn in a rare coin (1 of only 4 discovered to date). She was let off after it was revealed she had received it before the act came into law.