The carcass of the fish, thought to have died of natural causes, needed 15 people to haul it to shore.
Jasmine Santana, who works for the Catalina Island Marine Institute, revealed that the creature can grow up to 50ft, and is rarely seen as it dives 3,000ft deep.
‘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.’
According to CMI, the deep-water pelagic fish is the longest bony fish in the world.
‘We’ve never seen a fish this big,’ said Mark Waddington, senior captain of the Tole Mour, CIMI’s training ship. ‘The last oarfish we saw was three feet long.’
It will be buried in the sand until it decomposes and then its skeleton will be reconstructed for display.