Who says the Loch Ness monster isn't real? A snorkeling marine science instructor made the discovery of a lifetime on Tuesday when she discovered the carcass of an 18-foot-long oarfish, a serpent-like creature. "We've never seen a fish this big," said a senior captain of a sail training ship at the Catalina Marine Institute. "The last oarfish we saw was three feet long." Sightings of the oarfish, which can grow up to 50 feet, are extremely rare since the animal dives more than 3,000 feet deep into the ocean. The fish appears to have died of natural causes and will be buried in the sand to decompose then its bones will be reconstituted for display.