Large unknown animals reported at sea and in deep lakes, from the sea serpents of sailors’ tales to lake monsters such as Nessie and Champ. Evidence is anecdotal or disputed, and many sightings have been traced to known animals, debris or hoaxes.[1],[2]
By the Project Strange team · Not yet reviewed line by line · 4 sources
On this page
At a glance
- Also known as
- Sea serpent · Lake monster
- Subject
- Folklore · Reported sightings
- Sourcing
- 4 sources listed · 4 cited inline. Not yet reviewed line by line.
Background
BackgroundHistory, folklore and cultural context.
Sea serpents feature in sailors’ accounts and folklore for centuries. Explanations offered for particular sightings include whales entangled in fishing gear and debris, giant squid and the long, undulating giant oarfish.[2]
The Loch Ness Monster became internationally famous in 1933. The earliest report of a monster near Loch Ness appears in Adomnán’s 7th-century Life of St Columba, written about a century after the events it describes.[1] The famous 1934 "surgeon’s photograph" was exposed as a fake — reportedly a model made with a toy submarine — and the scientific community explains sightings as hoaxes, wishful thinking, and misidentification of known animals, objects and natural phenomena.[1]
An environmental DNA survey of Loch Ness in 2018 found no reptile DNA and no DNA from large fish, but a lot of eel DNA; its leader, Neil Gemmell, said he could not rule out unusually large eels, though none has been found.[1]
What witnesses describe
Witness claimsFeatures that recur in accounts. These are claims, not established facts.
- Classic sea serpent: elongated neck, small head, humped body above waterline
- Plesiosaur-type: long neck, four flippers, estimated length 15–30 feet
- Giant squid-type: massive cephalopod with elongated tentacles
- Often seen briefly at the surface before submerging rapidly
- Wake and wave patterns inconsistent with known marine mammals
- Reported from freshwater lochs and lakes as well as oceans
- Photographed objects show unusually large silhouettes under sonar
Notable cases
Each case is labelled by the kind of account it rests on.
1977Pacific Ocean, off New ZealandDocumented
Zuiyo Maru carcass
In 1977 the Japanese trawler Zuiyō Maru hauled up a decomposed carcass off New Zealand whose shape led to speculation that it was a sea serpent or plesiosaur.[3]
Read the story as commonly toldHide the story
Unverified: this is the traditional telling of the case. Its details have not been checked against sources and may be inaccurate.
A Japanese fishing trawler hauled up a decomposed carcass with a long neck, small head, and four flippers. Japanese scientists examined samples before the crew returned it to sea. Some identified it as a decomposed basking shark; others noted features inconsistent with known species.
Disputed or contrary evidence
Analysis of amino acids in its muscle tissue later indicated it was most likely a basking shark; decomposing basking sharks lose their lower jaw and fins first, leaving a "long-necked" shape.[3]
Material: Photographs and tissue samples
1987Loch Ness, ScotlandDocumented
Operation Deepscan
In 1987, 24 boats with echo-sounding equipment swept Loch Ness side by side. BBC News reported sonar contact with an unidentified object of unusual size and strength.[1]
Read the story as commonly toldHide the story
Unverified: this is the traditional telling of the case. Its details have not been checked against sources and may be inaccurate.
24 boats with sonar equipment swept Loch Ness simultaneously. Three sonar contacts were recorded at depths of 180 feet — larger than any known fish in the loch.
Disputed or contrary evidence
On re-scanning, the images seemed to show debris on the loch bed, with movement in three pictures; Loch Ness researcher Adrian Shine suggested seals. A tree stump filmed during the survey closely resembled an earlier "gargoyle head" photograph.[1]
Material: Sonar records
2003Lake Champlain, USADocumented
Champ echolocation recordings
In 2003, working for a Discovery Channel programme, the Fauna Communications Research Institute recorded sounds in Lake Champlain similar to those of beluga whales or dolphins, neither of which lives in the lake. A published article described them as likely echolocation.[4]
Read the story as commonly toldHide the story
Unverified: this is the traditional telling of the case. Its details have not been checked against sources and may be inaccurate.
Researchers using hydrophones recorded a bio-sonar signal in Lake Champlain inconsistent with any known animal in the lake. The signal resembled the echolocation pattern of a beluga whale, thousands of miles from its range.
Disputed or contrary evidence
None of the lake’s known native animals is able to echolocate, and the source of the sounds has not been identified. The best-known Champ photograph (Sandra Mansi, 1977) was reportedly taken in a bay no deeper than 14 feet, which Joe Nickell argues makes a giant animal unlikely.[4]
Material: Audio recordings
Explanations
InterpretationGrouped by the kind of explanation, not ranked by likelihood.
Conventional explanations
Known animals, natural processes, perception, memory, or hoaxes. These rely on things that are well established; whether one fits a particular case depends on the case.
- Giant oarfish or other long deep-sea fish seen from above
- Optical illusion — waves, logs, and known animals misperceived
Unconfirmed natural or human explanations
Would require an undiscovered species, an unrecognised natural effect, or secret human activity. Possible in principle, but not demonstrated.
- Surviving plesiosaur population in deep lakes and ocean trenches
- Unknown species of elongated pinniped or serpentine cetacean
- Genuine undiscovered megafauna — statistically probable given ocean coverage
References
Numbered as cited in the text; sources not cited inline are listed afterwards as background reading.
- 1.Loch Ness MonsterWikipedia
- 2.Sea serpentWikipedia
- 3.Zuiyo-maru carcassWikipedia
- 4.Champ (folklore)Wikipedia
Known gaps
- An earlier version of this entry dated the Champ recordings to 2019 and said Operation Deepscan recorded "three sonar contacts at 180 feet — larger than any known fish". Our sources date the recordings to 2003 and describe the Deepscan results differently.
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Suggest an editCommunity reports
Top-voted reports from Project Strange members in the Cryptids category. These are first-hand accounts, not verified events.
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