"It just amazed me," Jeff Chace, director of the Catalina Island Marine Institute, said after 15 people pitched in to lug the "leviathan" onto the island's shore.
"This is a once-in-a-lifetime discovery," he told the Los Angeles Times.
An instructor from the institute snorkeling in 20 feet of water Sunday stumbled upon the carcass after seeing a "half-dollar sized eye staring at her from the sandy bottom," Chace said.
The giant oarfish -- rarely seen dead or alive -- is the longest bony fish species that can reach more than 56 feet in length and is "likely responsible for sea serpent legends throughout history," the institute said.
Chace said since the institute has no way to store the carcass it plans to bury the fish in about 3 feet of sand until it decomposes and then work on mounting the skeleton for display.