Sea serpent

Natural history

An apparent eye-witness account is given by Aristotle in his work Historia Animalium on natural history. Strabo makes reference to an eyewitness account of a dead sea creature sighted by Poseidonius on the coast of the northern Levant. He reports the following: "As for the plains, the first, beginning at the sea, is called Macras, or Macra-Plain. Here, as reported by Poseidonius, was seen the fallen dragon, the corpse of which was about a plethrum [30 m or 100 feet] in length, and so bulky that horsemen standing by it on either side could not see one another, and its jaws were large enough to admit a man on horseback, and each flake of its horny scales exceeded an oblong shield in length." The creature was seen sometime between 130 and 51 BC.

Norway, 16th century

Swedish ecclesiastic and writer Olaus Magnus included illustrations of sea serpents and other various marine monsters on his illustrated map, the Carta marina. In his 1555 work History of the Northern Peoples, Olaus gives the following description of a Norwegian sea serpent:

Those who sail up along the coast of Norway to trade or to fish, all tell the remarkable story of how a serpent of fearsome size, from 200 feet [60 m] to 400 feet [120 m] long, and 20 feet [6 m] wide, resides in rifts and caves outside Bergen. On bright summer nights this serpent leaves the caves to eat calves, lambs and pigs, or it fares out to the sea and feeds on sea nettles, crabs and similar marine animals. It has ell-long hair hanging from its neck, sharp black scales and flaming red eyes. It attacks vessels, grabs and swallows people, as it lifts itself up like a column from the water.

Norwegian Bishop Erik Pontoppidan (1698–1764) did not disbelieve the existence of sea serpents themselves, but doubted they would prey on ships and feed on humans, being more cautious-minded in that respect than Archbishop Olaus (of Uppsala). Nevertheless, a number of reports were made by sailors at the time that sea serpents would destroy ships by wrapping the ship in coils of their body and pulling it underwater. Sailors threatened by a sea serpent were said to have thrown large objects such as paddles or shovels overboard in the path of the serpent, hoping that the serpent would take the object and leave without destroying the ship.

Greenland in 1734

Rev. Hans Egede, a Dano-Norwegian clergyman who was an early explorer and surveyor of Greenland, gave an 18th-century description of a sea serpent witnessed by his party. In his journal he wrote:

On the 6th of July, 1734, there appeared a very large and frightful sea monster, which raised itself so high out of the water that its head reached above our main-top (top of the mainmast). It had a long, sharp snout, and spouted water like a whale; and very broad flappers. The body seemed to be covered with scales, and the skin was uneven and wrinkled, and the lower part was formed like a snake. After some time the creature plunged backwards into the water, and then turned its tail up above the surface, a whole ship-length from the head. The following evening we had very bad weather" ―translated in Henry Lee (1883).

Egede also wrote on the same sea-monster sighting in his book, noting that the beast was spotted at the 64th degree of latitude, and was as thick or "bulky as the Ship, and three or four times as long". Egede himself did not supply a sketch in this otherwise well-illustrated book, but the missionary named Bing who was his comrade drew a sketch, which is reproduced in Henry Lee's work.

Bing further described this creature as having reddish eyes, almost burning with fire. This convinced Bishop Pontoppidan that this was different from the type of sea serpent seen by others. From Bing's drawing, Pontoppidan estimated the creature to be considerably shorter than the length of a cable rope, or 100 fathoms (200 m (220 yd)) attested by multiple witnesses, and the pair of fins which were attached "below the waist (Danish: liv)" in Pontoppidan's view, was another unusual feature.

Lee proposed a rational explanation that this sea-serpent was a misapprehended sighting of what was actually the exposed head and one tentacle of a giant squid (Cf. figure above left).

New York exhibition in 1845

In 1845, a 35 m (115 ft) long skeleton allegedly belonging to an extinct sea serpent was exhibited in New York City by Albert C. Koch. The claim was debunked by Prof. Jeffries Wyman, an anatomist who went to see the skeleton for himself. Wyman declared that the skull of the animal had to be mammalian in origin, and that the skeleton was composed of bones of several different animals, including an extinct species of whale.

Portuguese waters, 1848

On 6 August 1848 Captain M'Quhae of HMS Daedalus and several of his officers and crew (en route to St Helena) saw a sea serpent which was subsequently reported (and debated) in The Times. The vessel sighted what they named as an enormous serpent between the Cape of Good Hope and St Helena. The serpent was witnessed to have been swimming with 1.2 m (4 feet) of its head above the water and they believed that there was another 18 m (60 feet) of the creature in the sea. Captain M'Quhae also said that "[The creature] passed rapidly, but so close under our lee quarter, that had it been a man of my acquaintance I should have easily recognized his features with the naked eye." According to seven members of the crew, it remained in view for around twenty minutes. Another officer wrote that the creature was more of a lizard than a serpent. Evolutionary biologist Gary J. Galbreath contends that what the crew of Daedalus saw was a sei whale.

A report was published in the Illustrated London News on 14 April 1849 of a sighting of a sea serpent off the Portuguese coast by HMS Plumper.

On the morning of the 31st December, 1848, in lat. 41° 13'N., and long. 12° 31'W., being nearly due west of Oporto, I saw a long black creature with a sharp head, moving slowly, I should think about two knots [3.7 km/h; 2.3 mph] ... its back was about twenty feet [6 m] if not more above water; and its head, as near as I could judge, from six to eight [1.8 to 2.4 m] ...There was something on its back that appeared like a mane, and, as it moved through the water, kept washing about; but before I could examine it more closely, it was too far astern

— "A Naval Officer"

Brazilian waters, 1875

In 1875, Captain George Drevar reported a sighting by the crew of the Pauline near Cape São Roque:

The weather fine and clear, wind and sea-moderate. Observed some black spots on the water, and a whitish pillar, about thirty feet high above them. At the first glance I took all to be breakers as the sea was splashing up fountain-like about them, and the pillar a pinnacle rock, bleached with the sun; but the pillar fell with a splash, and a similar one rose. They rose and fell alternately in quick succession, and good glasses showed me it was a monstrous sea-serpent coiled twice round a large sperm-whale. The head and tail parts, each about thirty feet long were acting as levers, twisting itself and victim round with great velocity. They sank out of sight about every two minutes, coming to the surface still revolving; and the struggles of the whale and two other whales, that were near, frantic with excitement, made the sea in their vicinity like a boiling cauldron; and a loud and confused noise was distinctly heard. This strange occurrence last [sic] some fifteen minutes, and finished with the tail portion of the whale being elevated straight in the air, then waving backwards and forwards, and lashing the water furiously in the last death struggle, when the body disappeared from our view, going down head foremost to the bottom, where no doubt it was gorged at the serpent's leisure; and that monster of monsters may have been many months in a state of coma, digesting the huge mouthful. Then two of the largest sperm-whales that I have ever seen moved slowly thence towards the vessel, their bodies more than usually elevated out of water, and not spouting or making the least noise, but seeming quite paralized [sic] with fear; indeed, a cold shiver went through my own frame on beholding the last agonizing struggle of the poor whale that had seemed as helpless in the coils of the vicious monster as a small bird in the talons of a hawk. Allowing for two coils round the whale, I think the serpent was about 160 or 170 feet long, and 7 or 8 feet in girth. It was in colour much like a conger-eel; and the head, from the mouth being always open, appeared the largest part of its body. I wrote thusfar [sic], little thinking I would ever see the serpent again, but at seven A. M., July 13, in the same latitude, and some eighty miles east of San Roque I was astonished to see the same or a similar monster. It was throwing its head and about 40 feet of its body in a horizontal position out of water as it passed onwards by the stern of our vessel.

Natural explanations

R.L. France proposed in a 2016 paper for the International Journal of Maritime History that a significant number of sea serpent sightings, including nineteenth century accounts of serpents attacking whales, were due to the misidentification of whales entangled in fishing gear and maritime debris.

Due to their size, elongated bodies, and undulating swimming pattern, giant oarfish are also presumed to be responsible for some sea serpent sightings. A 2016 episode of the TV series River Monsters, seeking to uncover the origin of the sea serpent myth, concluded that the most likely culprit was the oarfish.

In a 2023 article for Fate, Karl Brandt suggested well-known sea serpent sightings could be explained by harpooned sperm whales held fast to their hunters’ overturned rowboats. The boats would accumulate debris at the surface which could stretch for hundreds of yards while appearing to be propelled through the water by unknown means. The theory was supported by the majority of sightings in Norwegian fjords occurring ‘during the summer months of June to August when the whales are most-plentiful’.

In media

• C. S. Lewis's The Chronicles of Narnia features a sea serpent as one of many obstacles in The Voyage of the Dawn Treader, along with the 1989 TV serial and the 2010 film based on it.
• Beany and Cecil, featuring a sea sick sea serpent. Revived as The New Beany and Cecil Show by producer DIC Entertainment.