The Caltrans Crew's Sea Serpent off Stinson Beach

Monday, 31 October 1983. Halloween. A Caltrans maintenance crew from Novato had been sent to clear a slide on State Route 1, the Shoreline Highway, on a hillside overlooking Stinson Beach in Marin County. Below them lay the mouth of Bolinas Bay.

It was shortly before 2 p.m., by the account drawn from the San Francisco Chronicle. A later field guide by Loren Coleman and Patrick Huyghe puts it at 2:30 pm. The flagman, known in the reports only as Gary, saw it first. Something was swimming toward the cliff. Gary radioed crew member Matt Ratto to get his binoculars.

Ratto watched through the lenses. "There were three bends, like humps, and they rose straight up. Then the head came up to look around." The crew placed it a quarter of a mile away and 100 yards offshore. They judged it at about 100 feet. Coleman and Huyghe would record it as five feet in diameter, with a small head and neck.

Truck driver Steve Bjora saw only two humps. "The sucker was going 45 to 50 miles an hour. It was clipping. It was boogying. It looked like a long eel." Behind it came about 100 birds and two dozen sea lions.

The whole sighting lasted about 30 seconds. The head was up for about 2 seconds.

Marlene Martin of the Novato crew was the central witness in the Caltrans account. Martin was unavailable to the Chronicle, so Martin's daughter spoke instead. "Mom came home and told us it was the biggest thing she ever saw in her life, and my Mom doesn't lie. She said it made 'Jaws' look like a baby." Martin told the family there were four humps.

According to Caltrans, Martin became an instant celebrity. Newspapers, radio, TV and scientists came calling. Calls arrived from Texas, Florida, Oregon, Utah and Southern California. So did disbelief and ridicule. "You really can't understand what we're talking about unless you've seen it yourself." Later Martin saw a wood carving by a Bolinas artist who had reportedly seen a similar animal a few years back. "The shape of its body was almost identical to what I saw."

Steve Rubenstein's Chronicle story opened with a line that stuck: "A 100-foot sea serpent was reported off Stinson Beach by five people who had not been drinking." Jack Svenson, a biologist at Point Reyes Bird Observatory, offered a whale. "A whale surfacing in backlit sunshine, silhouetted with a lot of glare, could look like the Loch Ness Monster." Yet he also spoke of "periodic sightings", and allowed that "there may be all sorts of prehistoric creatures swimming around out there that we know nothing about."

A spokesman at the Corona del Mar marine facility suggested a pilot whale or a gray whale, or "three or four porpoises in a line jumping from the water." A giant squid has been raised too. No hoax was ever alleged. No photograph, film or physical trace was ever reported.

The International Society of Cryptozoology wrote the case up in its newsletter that winter. Caltrans told it in its staff magazine, Fourword, in January 1984, in an article by Jeff Weiss, and reprinted it in Fall 2023. Others came forward. Roland Curry, 19, was on the beach and told the Weekly World News it was his second sighting in less than a week. On 2 November, surfers at Costa Mesa reported a sea serpent of their own. The case is sometimes filed with Cadborosaurus, the serpent tradition of the Pacific coast.