The Seljord serpent overturns Gunleik Andersson Verpe's boat on Seljordsvatnet

Seljordsvatnet is a lake about 13 km long in Seljord municipality, Telemark. It is home to Norway's best-known lake monster, known today as Selma. Since 1989 the serpent has appeared in gold on red on Seljord's coat of arms. And every telling of the legend goes back to one crossing.

1750. One source says it was summer. Gunleik Andersson Verpe, a man from Bø, had bought the farm Nes. He was moving house by water, rowing his belongings from Ulvenes to Nes on two boats or rafts.

Out in the middle of the lake, a sea serpent surfaced. A sjøorm. It attacked one of the two craft and overturned it. Telemarkshistorier says it was the rear raft. The GUST Norway account puts it more starkly. Suddenly and without warning, he was "attacked by a sea-horse".

Of the creature itself, the story keeps almost nothing. No size. No colour. No sound. Only the attack, and the overturned boat. Sources disagree about Gunleik's fate. One says he came through unharmed. The municipality notes that the legend says nothing about what happened to him. One summary says he drowned. Either way, the story spread rapidly. From then on, people crossing the lake carried axes, boat hooks or long poles to defend themselves.

No record written in 1750 survives. The earliest printed text about the creature comes from Hans Jacob Wille, a priest and topographer born in Seljord. In 1786 he wrote: "Den gaaer under Vandet, som en Aal." It moves under the water like an eel. Some years earlier, he added, it had bitten a man on his big toe as he waded barefoot across the Laxhøl river. Wille called it highly venomous.

But Wille's animal is small, and he does not mention the boat. The 1750 account most likely reached print through local tradition collected by Halvor J. Sandsdalen in Ormen i Seljordsvatnet, 1976. English retellings drifted further still. In translation, the overturned boat became "rounded a rowboat", and the sea serpent became a "sea storm".

The sightings never stopped. In 1920 Eivind Fjodstuft at Sinnesodden described something 15 to 20 m long, slender and black, with a head like a crocodile. In 1998 Jan-Ove Sundberg led an international expedition by the Global Underwater Search Team, with the Discovery Channel holding exclusive filming rights. The team brought echo sounders, side-scan sonar and two remote-controlled submarines.

They found nothing conclusive. Large sonar contacts were identified as big fish or schools of fish. In 2000 GUST recorded unexplained sounds, said to resemble "a cross between a snorting horse and an eating pig". Sceptics point out that the lake is far too small to feed an animal of that size, and has existed for only about 10,000 years.

In 2017 Seljord set up a 24-hour live YouTube stream of the lake. Visit Seljord leader Hilde Hagen Nilsen explained: "many doubt whether there is a lake serpent… so we are trying this to perhaps be able to see it directly". By the water stands Sjøormtårnet, the 17 m Sea Serpent Tower designed by Rintala Eggertsson. It all began with a man, a moving load and a boat that never reached Nes upright.