A marine biologist has made the discovery of a lifetime - the five-metre-long silvery carcass of the creature believed to be the origin of sea serpent legends.
Jasmine Santana of the Catalina Island Marine Institute (CIMI) was snorkelling with colleagues in Toyon Bay, southern California when she spotted something shimmering in the water.
She dragged the eel-like beast by the tail for more than 20m, others waded in to the sea and helped her bring it to shore.
After taking a closer look she discovered it was an oarfish, which can grow up to 15m.
"Jasmine Santana was shocked to see (a) half-dollar sized eye staring at her from the sandy bottom," the institute said in a statement.
"Her first reaction was to approach with caution, until she realised that it was dead."
Oarfish are deep-water pelagic fish and the longest bony fish in the world, according to CIMI.
Because oarfish dive more than 3,000 feet (914 metres) deep, sightings of the creatures are rare and they are largely unstudied.
"We've never seen a fish this big," said Mark Waddington, senior captain of the Tole Mour, CIMI's sail training ship.
"The last oarfish we saw was three feet long."
Tissue samples and video footage were sent to be studied by biologists at the University of California in Santa Barbara.
It will be buried in the sand until it decomposes and then its skeleton will be reconstructed for display.
The fish apparently died of natural causes.