The Gloucester Sea Monster is one of America’s earliest and most famous sea serpent legends, originating from Gloucester, Massachusetts in the early 19th century. This strange creature reportedly haunted the waters off the New England coast for decades terrifying fishermen, mystifying scientists, and sparking one of the first recorded American cryptid investigations.
“It moved with such rapidity that no boat could overtake it… its motion was like that of a caterpillar, alternately rising and falling.”
— Gloucester eyewitness testimony, 1817
The Gloucester Sea Monster — Overview
- First major reports: August 1817
- Location: Gloucester Harbor, Cape Ann, Massachusetts
- Type: Long, serpent-like sea creature
- Reported length: 40–100 feet
- Behavior: Slithering or undulating through the water, sometimes coiling or raising its head like a snake
In August 1817, several fishermen near Gloucester Harbor reported seeing an enormous, serpent-like creature swimming just offshore.
Eyewitness Descriptions:
- Length: Between 50–100 feet
- Thickness: About that of a barrel or large tree trunk
- Color: Dark brown or black with light-colored spots
- Head: Snake- or turtle-like, occasionally raised above the water
- Movement: The creature moved in a vertical, undulating motion, with humps (10–12 in a line) appearing as it swam.
Witnesses claimed it swam against the current and moved faster than a whale.
Soon, entire crowds gathered along the coast to watch it. According to reports, dozens of fishermen and townspeople saw the monster during the late summer of 1817. The reports drew the attention of the Linnean Society of New England, a scientific organization based in Boston. Members, including Dr. Jacob Bigelow and Dr. John C. Warren, investigated the sightings.
They interviewed firsthand witnesses and even claimed to have found a baby sea serpent caught by a local fisherman.
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The small creature was about 3 feet long and had snake-like features.
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It was preserved in alcohol and displayed publicly for study.
The Linnean Society concluded that the Gloucester creature might be a new species of marine serpent, naming it Scoliophis Atlanticus.
However, the preserved “baby serpent” was later examined by other scientists — who determined it was just a common snake, deformed by the alcohol preservative.
Later Sightings and Recurring Encounters
1818–1820s
Reports continued for several years.
- Fishermen along Cape Ann, Ipswich, and Marblehead described seeing the serpent rise from the water.
- In one dramatic report, a crew of sailors claimed the monster followed their ship for several minutes before diving under.
1850s–1880s
The creature was sighted less frequently but never entirely disappeared from local lore.
- One report described a massive “black object” thrashing in the water near Nahant.
- Another fisherman said it “rose like a wall” out of the sea and vanished with a loud splash.
1950s–1970s
A few modern sightings echoed the old tales:
- In the 1950s, a Gloucester lobsterman reported seeing a “snake-like creature” with “humps like a row of barrels.”
- In 1962, a tourist claimed to have photographed a strange undulating figure offshore, though the image was never verified.
Theories:
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Oarfish: Some believe the creature was a large oarfish, a real species that can grow over 30 feet and move in a serpentine fashion.
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Giant eel or sea snake: Could have been an enormous eel or unrecognized marine species.
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Misidentified whale or seals: Groups of seals or a whale’s back moving through the waves may have created the illusion of a “serpent.”
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Folklore / mass hysteria: Once the story gained traction, observers may have exaggerated or misinterpreted what they saw.
