SF Sea Serpent - Sightings
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Sea Serpent Sightings in SF Bay

Historic and Modern Day Reports of Unknown Sea Creatures in San Francisco Bay...

By Greg Latimer
Mysterious Destinations Research Director

The busy waters of San Francisco Bay may not seem the likeliest place to find reclusive cryptids like sea serpents, but both history and current events seem to contradict that assumption.

Recorded sightings of large, serpentine sea creatures in San Francisco Bay date back to the 1800’s and continue to the present day. Prior to that, some of the animals carved into totem poles or painted on rocks by Native Americans resemble sea serpents.

Recent sightings include an observation of a serpentine animal raising its head and long neck from the water near the Golden Gate and a woman who saw a large serpentine creature consume a whole pelican in one bite.

But the most compelling observations, including video, are coming from twin brothers Bill and Bob Clark, who have been searching the bay for serpents after they had a very close encounter with one in 1985.

The Clark Brothers Embark on a Mission

The Clark brothers’ fascination with the San Francisco Bay Sea Serpent began on the morning of February 5, 1985 while they were sipping coffee parked along the shore side walkway at Marina Green in San Francisco. They observed some sea lions cavorting about 150 yards offshore directly in front of them, and while they were watching the group of sea lions they noticed what they thought was another sea lion approaching the group. When it got within a few yards of the group of sea lions it suddenly raised its head and a portion of its body approximately 10 feet straight up out of the water and then it lunged forward into the group of sea lions. The sea lions scattered with one of them making a mad dash for the shoreline in front of their car.

As it was being chased by the large serpentine marine animal, the sea lion swam over a submerged rocky ledge that, due to an extremely high tide that day, was covered by about three feet of water. The creature’s pursuit of the sea lion caused it to crash onto the submerged rocky ledge, partially exposing itself approximately 20 yards away from where the stunned brothers were sitting in their car.

For a full video of the Clark brothers describing this incident, which includes a detailed description of the animal, click here. For a link to the Clarks description of this incident on their blog, click here

Since then the Clark brothers have continued to make observations and compile them on their blog. For a link to that blog, click here

Analysis of Video

One of the videos captured by the Clark brothers is particularly compelling. That video was taken from an elevated observation point at Fort Mason looking out toward Alcatraz Island. Even though the object is well distant from the camera, and initially appears to be birds on the water, you will see it do something birds don’t do… Turn in a full circle as it submerges. To see the video of the possible sea serpent, click here.

For a video of the Clark brothers at the Fort Mason observation point describing the circumstances surrounding the video, click here.

Clifford Paiva of BSM Research Associates in California City, California reviewed this video and others.

Paiva is a missile defense and space sciences physicist who also uses his image analysis software and expertise to examine evidence on a variety of issues including modern day mysteries. His work was featured on he History Channel's Monsterquest episode on Flying Monsters where he performed aerodynamic and image processing work. For that episode missile defense target detection and extraction techniques were applied to a video that appeared to show a Pterosaur. These same techniques were used with the Clark brothers’ video.

In his report he stated unequivocally that: “BSM Associates determines that the video submitted by the Clark Brothers reveals an unidentified group of marine animals operating in the San Francisco Bay, 26 January 2004”.

Regarding the video linked to this article, the report stated: “A single animal was observed to reverse it’s heading 180 degrees… This motion yielded good approximations of the animal’s length and head-to-body scaling ratio… This marine animal indicates a total length of at least 75 feet” based on a variety of technical calculations made by Paiva.

The BSM report also speculates on the identity of the creature: “Although sea snake seems to be the most tenable conclusion, the authors do not dismiss the possibility of Elasmosaur for these animals.” An Elasmosaur (or Elasmosaurus) is a prehistoric water creature thought to be extinct. To check the Wikipedia page on these animals, click here. (Of note: The Wikipedia description gives a maximum size on Elasmosaurus to be just over 40 feet, much shorter that the BSM image analysis. There are also inconsistencies with the Clark brothers’ description and the build of an Elasmosaurus.)

Paiva also added a warning: “Close observations of SF Bay specimens are certainly not well advised. Although the authors do not agree with the existence of sea monsters, we do recognize the existence of very large and potentially dangerous marine animals operating normally in what they may otherwise consider their winter, warm-water habitat”.

Cyptozoologist Loren Coleman of the International Crytozoology Museum in Portland, Maine reviewed the Clark brothers’ video in 2007 and made a noteworthy comparison of the object seen in the video with an illustration made in the 1800’s based on a witness description of serpentine animal observed off the coast of New England. To check Coleman’s comparison, click here.

The Travel Channel followed up on the Clark brothers’ video with an exploration of their own, which included a night dive into the Bay. For a link to the Travel Channel’s “teaser” on this episode, click here. (We were unable to locate the full episode, but we’ll keep trying and publish a link here as soon as it is obtained.)

The Clark brothers aren’t the only ones spotting sea serpents in San Francisco Bay and surrounding areas.

More Eyewitness Accounts

In November 1983, a construction crew working on Route 1 near Stinson Beach north of the Golden Gate Bridge saw a creature, underwater, approaching the land. They estimated it to be 100 feet long and about five feet in diameter. They described it as black in color. With binoculars they observed it throwing its head about and whipping it's body around in what appeared to be coils. MysteriousDestinationsMagazine.com was able to contact one of the members of this crew, who confirmed the sighting.

On February 28, 2006 a witness contacted the Clark brothers regarding an incident off Navarro Beach, about 125 miles north of San Francisco. The witness was on a fishing boat about a half-mile from shore fishing for salmon. They were chatting on the marine radio with nearby boats when the wife of one of the men on another boat said she could see a sea serpent nearby. They all were laughing about it until she told them where to look and when they looked over they saw the head and about eight feet of neck sticking out of the water in a kelp bed. They were able to get within 50 yards of it but when they tried to get closer it went straight down under the water and they didn't see it again after that.

Another witness posted a sighting in the comments section of an article about the Clarks posted on Crytomundo.com. She related the following:

“My husband and I live in the Candlestick Point condos off the 101 and saw the sea serpent twice in the summer of 2007. I saw it first while driving alone. It was undulating in and out of the water and I could clearly see what looked like several humps moving. We last saw it in August 2007. My husband saw it eat a pelican sitting in the water and those birds are huge. (This occurred) as I was driving and trying to watch the road. I didn’t see it happen, but immediately after we both witnessed a bunch of pelicans wildly dive-bombing the serpent in the water as if on the attack.”

In August of 2009 another witness saw something unexplainable in the bay while riding in a car. According to her description, a child in the car said he saw something in the water. She turned to look and observed an “enormous sea serpent in silhouette against the dark water and night sky with it's head and neck section poised out of the water at least six feet, whiskers, or appendages on its head”. She could clearly see the eyes and it was not too far from the shoreline, and was stationary in the water with two large coils rising behind it,” according to the witness. The arches rose behind the head and neck roughly four feet high, then the head moved slightly back and forth but the rest of the animal remained stationary in the water, the witness said. She only saw it for a brief period as the car sped past but she had no doubt about what she saw.

As recently as March 2013 the Clarks received a report from a witness who had observed, "This amazing creature you have documented curled out of the water (just the body)… I caught (sight of) the end of a tail...". This sighting was at Baker Beach, just south of the Golden Gate. (In the “Where to Seek the Sea Serpent” article in this edition of MysteriousDestinationsMagazine.com an observation area along the Land’s End Trail is mentioned. This observation point allows an elevated view and is just south of Baker’s Beach. For a link to that article, click here.)

Historic Sightings

On October 31, 1875 the Daily Alta California published two interviews with men who stated that had seen a sea serpent in San Francisco Bay. The newspaper proudly stated, “The source(s) of our information of the subject in hand are so reliable that, for one, we are inclined to the opinion that the sea-serpent is a reality”.

The first witness in the article is Colonel J. W. Wood, “a ticket taker at Long Wharf” who is described as man of “extreme modesty, careful reliability and general trustworthiness”.

Col. Wood stated: “It was about twelve months ago this summer, quite early in the morning -- between five and six o'clock -- that I first saw this remarkable snake. It was about one third of a mile north from the center of Long Bridge (a structure now covered with landfill and buildings), and appeared to be sporting in the water, which it agitated violently and lashed into a foam.”

He described the animal as standing “Erect from the water as one of the piles in the slips, and in the uniformity of its diameter I would judge its measure to be from 14 to 16 inches. Its height above the surface of the water was ten to fifteen feet. The head resembled that of a lizard or bullfrog, and was dazzling black, while the throat was pure white. From the head, just above a lizard shaped mouth protruded an inch or more a pair of deep black eyes, half as large as ordinary saucers”.

Col. Wood was even able to observe the creature’s body. “The body, or so much as I saw was striped in harmonious shades of black and brown, on the back and sides, the stripes running lengthwise, while the belly was almost white. Running down the center of the back was plain to be seen a sort of fin-like ruffle, about four inches in width,” he told the Daily Alta.

The second witness was Winston G. Dinsmore, the owner of a drug store located at 1059 Broadway, whose reputation was described by the newspaper as: “One of our pioneers and a most reputable citizen -- a forty-niner, and a man who, when he talks, knows what he is talking about, and who doesn't talk much for fun”. The article also noted that Dinsmore had “achieved a valuable notoriety as a dealer in an extra choice brand of Mozart cigars”.

He had witnessed a sea serpent in the bay within days of his interview. Dinsmore described the serpent as: “Swimming along with the rapidity of a steam-tug, near the old ferry landing, or Long Bridge. Its head was raised about four feet out of the water, and at intervals be could see a curvature in its huge body at a distance not less than twenty five or thirty feet from its head”.


From prehistory to present day, reports keep coming in of unknown serpentine sea creatures in the San Francisco Bay area, but a preponderance of irrefutable evidence is still pending. That’s why MysteriousDestinationsMagazine.com is launching the San Francisco Bay Sea Serpent Search in cooperation with Bill and Bob Clark, whose sighting of a serpent in 1985 sparked them to initiate their own search. To find out how you can join the San Francisco Bay Sea Serpent Search, click here.