The Naden Harbour "Cadborosaurus" carcass, retrieved from the stomach of a sperm whale and photographed in October, 1937. It was identified as a fetal baleen whale.
|Sub grouping||Sea monster|
"Cadborosaurus willsi", nicknamed Caddy, is an alleged sea serpent reported to be living on the Pacific Coast of North America. Its name is derived from Cadboro Bay in Greater Victoria, British Columbia, and the Greek root word "saurus" meaning lizard or reptile. Reports describe it as being similar in form and behavior to various popularly named lake monsters such as "Ogopogo" of Okanagan Lake in British Columbia and to the Loch Ness Monster of Scotland.
Cadborosaurus willsi is said by witnesses to resemble a serpent with vertical coils or humps in tandem behind the horse-like head and long neck, with a pair of small elevating front flippers, and either a pair of hind flippers, or a pair of large webbed hind flippers fused to form a large fan-like tail region that provides powerful forward propulsion.
Dr. LeBlond director of Earth and Ocean Sciences at UBC and Dr. Blousfield retired chief Zoologist of the Canadian Museum of Nature state every elongated animal has been put forward as an explanation for Caddy. These animals include Conger eels, humpback whales, elephant seals, ribbon or oar fish, basking sharks and sea lions. LeBlond and Blousfield state no known creature matches the characteristics found in over 200 sightings collected over a century noting Caddy is described as having flippers both anterior and posterior.
Creatures identified as Cadborosaurus 
Sea lion 
In 1943 two police officers, Inspector Robert Owens and Staff Sergent Jack Russell saw a “huge sea serpent with a horse like head” in Georgia Strait. Later “with a pair of binoculars Sgt. Russell saw that the strange apparition was a huge bull sea lion leading a herd of six sea lions…Their undulations as they swam appeared to form a continuous body, with parts showing at intervals as they surfaced and dived. To the naked eye, the sight perfectly impersonated a sea monster.” 
Giant oarfish 
There have been suggestions that Caddy could be an example of the king of herrings or giant oarfish (Regalecus glesne). This species can reach 17 m in length and weigh up to 300 kg; some think the red mane on the head and back of the giant oarfish resembles a horse head with mane. A modern illustration by David John, "based on LeBlond/Bousfield composite and eyewitness accounts" shows Caddy with a red mane.
"They're long and silvery and they undulate like a serpent would as they swim through the water," said H.J. Walker, a senior museum scientist at the Scripps Institution of Oceanography, which has several oarfish in its collection. 
Basking shark 
The carcass of a decomposing basking shark is often mistaken for Caddy and has fooled experts and laymen. A rotting basking shark may resemble a decomposing plesiosaur. The Plesiosaur shape is mistaken for Caddy.
First Nations accounts 
A native image that fits Caddy's description has been traditionally used throughout Alaska. The image indicates that Caddy or a Caddy-like creature moves north to Vancouver when the waters warm. The Inuit of Alaska have even put the picture on their canoes to keep the creature away. The Cadborosaurus is called "hiyitl'iik" by the Manhousat people who live on Sydney Inlet, "T'chain-ko" in Sechelt mythology, and "Numkse lee Kwala" by the Comox band of Vancouver Island.
There have been more than 300 claimed sightings during the past 200 years, including Deep Cove in Saanich Inlet, and Island View Beach, both like Cadboro Bay also on the Saanich Peninsula, also British Columbia, and also at San Francisco Bay, California.
Kelly Nash video 
In 2009, fisherman Kelly Nash purportedly filmed several minutes of footage featuring ten to fifteen (including young) creatures in Nushagak Bay. In 2011, a very short segment of the footage was shown on the Discovery TV show Hilstranded, where the Hilstrand brothers (from Deadliest Catch) apparently saw Nash's footage and unsuccessfully attempted to find one of the creatures.
Carcasses associated with Cadborosaurus 
- 1930: On November 10 at Glacier Island near Valdez a skeleton was found in ice. The skeleton was 24 feet long with flippers. Some of the remains were preserved in Cordova for scientific study. Creature thought to be a whale but undetermined.
- 1934: In November on Henry Island near Prince Rupert, badly decomposed remains about 30 feet long found. Dr. Neal Carter examined the remains. Creature identified as basking shark.
- 1937: In October a purported Cadborosaurus carcass was retrieved from the stomach of a sperm whale in Naden Harbour and photographed. A sample of this carcass was sent to the BC Provincial Museum, where it was tentatively identified as a fetal baleen whale by museum director Francis Kermode.
- 1941: A carcass called “Sarah the sea hag” was found on Kitsilano Beach. W.A. Clemens and I. McTaggert-Cowan identified it as a shark.
- 1947: In December at Vernon Bay, Barkley Sound, Vancouver Island a 45 foot creature was found. It was identified as a shark.
- 1950: In Delake, Oregon a creature was found with 4 tails and thick hair. It was identified as a whale shark.
- 1956: Somewhere near Dry Harbour south of Yakutat, Alaska a 100 foot long carcass was found with two inch long hair. Trevor Kincaid is quoted as saying “description fits no known creature.” W.A. Clemens identified the carcass as a Baird's beaked whale.
- 1962: In April near Ucluelet a 14 foot long carcass was found with elephant like head. The carcass was dragged ashore by Simon Peter and later thought to be an elephant seal.
- 1963: In September near Oak Harbor, Whidbey Island a carcass was found with a head resembling a horse. A. D. Welander of Fisheries thought it was a basking shark.
Purported live capture 
- 1968: In August, W. Hagelund claims to have caught a baby Caddy near De Courcy Island.
- 1991: In July, on Johns Island (San Juan Islands), Phyllis Harsh claims to have caught a small 2 foot baby Caddy and returned it to the water.
Television and media appearances 
Cadborosaurus has also been featured on the television documentary series Northern Mysteries.
- Bousfield, Edward L. & Leblond Paul H. (2000). Cadborosaurus: Survivor from the Deep. Heritage House Publishing.
- Vancouver Province Newspaper. Page 1., March 9, 1943
- December 03, 2010|By Tony Barboza, Los Angeles Times
- Heuvelmans B. (1968), In the wake of the sea-serpents. Hill & Wang, New York.
- - ., Naish, D. & McCormick, C. A. 2011. A baby sea-serpent no more: Reinterpreting Hagelund’s juvenile “Cadborosaur” report. Journal of Scientific Exploration 25, 497-514.
- Woodley, M. A., McCormick, C. A., & Naish, D. 2012. Response to Bousfield & LeBlond: Shooting pipefish in a barrel; or sauropterygian “mega-serpents” and Occam’s razor. Journal of Scientific Exploration 26, 151-154.
- Viegas, Jennifer. "Loch Ness Monster-like Animal filmed in Alaska?". Discovery News. Retrieved 27 August 2011.
- Daily Alaska Empire, November 28, 1930
- Vancouver Province Newspaper., November 23, 1934
- Vancouver Province Newspaper, November 23, 1937
- Vancouver Province Newspaper, October 16, 1937
- Vancouver Province Newspaper, March 5, 1941
- Seattle post Intelligencer, December 7, 1947
- Victoria Daily Times, March 7, 1950
- Life Magazine., June 8, 1956
- Vancouver Sun., April 14, 1962
- Whidbey News Times, October 3, 1963
- Hagelund, W. (1987), Whalers no more. Harbour Publishing, Madeira Park,BC.
- Bauer, A. M. & Russell, A. P. (1996). A living plesiosaur?: a critical assessment of the description of Cadborosaurus willsi. Cryptozoology 12, 1-18.
- Bousfield, E. L., & P. H. LeBlond (1995). "An account of Cadborosaurus willsi, new genus, new species, a large aquatic reptile from the Pacific coast of North America". Amphipacifica Vol 1 Suppl. 1: pp. 1–25, 19 figs.
- Coleman, Loren and Clark, Jerome. Cryptozoology A to Z: The Encyclopedia of Loch Monsters, Sasquatch, Chupacabras, and Other Authentic Mysteries of Nature with Jerome Clark (NY: Simon and Schuster, 1999, ISBN 0-684-85602-6).
- Jupp, Ursula. (1988, reprinted 1993). Cadboro: A Ship, A Bay, A Sea-Monster. Jay Editions.
- Wright, John D. (2009). Cryptids and Other Creepy Creatures. (ISBN 0-545-11959-6)
- (French) Caddy le serpent de mer canadien. sur Crypto-Investigations.com
- Cadborosaurus and the Naden Harbour carcass: extant Mesozoic marine reptiles, or just bad science?
- Cryptomundo: 15 Cadborosauruses? Maybe a few less.
- The Cadboro Bay Sea Serpent
- The Cadborosaurus Watch
- The Cryptid Zoo: Caddy
- MSNBC report on it, and 2009 video of suspected creature.
- http://blogs.sos.wa.gov/library/index.php/2012/09/dungenessie/, 1892 sighting near Dungeness, Washington