Captain Lorenz von Ferry's sea serpent off Molde, 1746

Late August, 1746. Lorenz von Ferry, a naval officer, was heading home from Trondheim in his yacht, eight men at the oars. It was a very calm and hot day. Near Molde, at a place called Jule-Naess, very probably the headland of Julneset, von Ferry sat reading a book.

He heard a kind of murmuring from the men at the oars. The man at the helm was keeping off from the land.

Something was swimming close by. Its head, held more than two feet above the water, resembled that of a horse. It was greyish. The mouth was quite black, and very large. It had black eyes and a long white mane that hung from the neck down to the surface. Behind the head and neck rose seven or eight folds, or coils. They were very thick. As far as the men could guess, a fathom lay between each one.

Von Ferry ordered the helmsman to keep the land again and come up with the creature. It passed by them, and they had to tack the vessel about. He took his gun, loaded with small shot, and fired. The animal plunged under water at once. The crew rowed to the spot, easy to mark in the calm, and lay upon their oars. They waited. It did not come up again. Where it went down, the water appeared thick and red. Perhaps the shot had wounded it, von Ferry wrote. The distance had been very little.

Five years later, on 21 February 1751, von Ferry set the story down in a letter to Johann Reutz in Bergen. The next day two of his oarsmen, Niels Petersen Kopper and Niels Nielsen Anglewigen, swore before the court at Bergen that it was strictly true.

Bishop Erik Pontoppidan printed the case in his Natural History of Norway, in Danish in 1752 and 1753, then in English in 1755. He used it, with other sworn testimony, to argue that sea serpents were real. It became one of the founding cases of the sea-serpent literature.

In Sea Monsters Unmasked, the naturalist Henry Lee suggested the coils were eight porpoises swimming in a line. A. C. Oudemans would have none of it. In The Great Sea-Serpent, in 1892, he argued that local seamen knew porpoises far too well to be fooled. He read the horse-like head as the angle of the neck, the wide nostrils and the mane. The grey colour was skin dried in the sun. To Oudemans, this was a giant long-necked, seal-like animal. A maned, horse-headed animal also fits the type Bernard Heuvelmans later called the merhorse.

The story grew in the retelling. In 1877 Chambers's Journal had the wounded beast pursue de Ferry so closely that he narrowly escaped with his life. The letter says nothing of the kind. A 2017 exhibition text gave it tentacles. Some American newspapers printed the year as 1756. The original remains simpler. A calm sea. A horse's head. A white mane. And red water where something went down and did not come up again.