In Norse mythology

Norse mythology

Norse mythology, a subset of Germanic mythology, is the overall term for the myths, legends and beliefs about supernatural beings of Norse pagans. It flourished prior to the Christianization of Scandinavia, during the Early Middle Ages, and passed into Nordic folklore, with some aspects surviving...

, Gandvik is a dangerous sea

Sea

A sea generally refers to a large body of salt water, but the term is used in other contexts as well. Most commonly, it means a large expanse of saline water connected with an ocean, and is commonly used as a synonym for ocean...

, known as 'Bay of Serpents' because of its tortuous shape. Saxo Grammaticus

Saxo Grammaticus

Saxo Grammaticus also known as Saxo cognomine Longus was a Danish historian, thought to have been a secular clerk or secretary to Absalon, Archbishop of Lund, foremost advisor to Valdemar I of Denmark. He is the author of the first full history of Denmark.- Life :The Jutland Chronicle gives...

 stated that Gandvik was an old name for the Baltic Sea

Baltic Sea

The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...

 (a name misspelt Grandvik in some translations). The legend presumably refers to Gulf of Bothnia

Gulf of Bothnia

The Gulf of Bothnia is the northernmost arm of the Baltic Sea. It is situated between Finland's west coast and Sweden's east coast. In the south of the gulf lie the Åland Islands, between the Sea of Åland and the Archipelago Sea.-Name:...

. However, there are two opposite theories about where Gandvik was situated, based on the peace treaty in Nöteborg 1323: in the Arctic Ocean

Arctic Ocean

The Arctic Ocean, located in the Northern Hemisphere and mostly in the Arctic north polar region, is the smallest and shallowest of the world's five major oceanic divisions...

 or the Gulf of Bothnia

Gulf of Bothnia

The Gulf of Bothnia is the northernmost arm of the Baltic Sea. It is situated between Finland's west coast and Sweden's east coast. In the south of the gulf lie the Åland Islands, between the Sea of Åland and the Archipelago Sea.-Name:...

. Starting from 1850s, the former received more support in that Sweden had extended far out to the Arctic Ocean, but since the 1920s the latter have gained more support. However, Hversu Noregr byggdist

Hversu Noregr byggdist

Hversu Noregr byggðist is an account of the origin of various legendary Norwegian lineages, which survives only in the Flatey Book. It traces the descendants of the primeval Finnish ruler Fornjót down to Nór, who is here the eponym and first great king of Norway, and then gives details of the...

, dating from the former part of the 13th century, is by most opinions referring to the White Sea

White Sea

The White Sea is a southern inlet of the Barents Sea located on the northwest coast of Russia. It is surrounded by Karelia to the west, the Kola Peninsula to the north, and the Kanin Peninsula to the northeast. The whole of the White Sea is under Russian sovereignty and considered to be part of...

when it uses the term Gandvik. (LUNDKVIST 1985)

Source: "Northern Scandinavia during the Middle Ages", part of "In honorem Evert Baudou" (1985), Sven Lundkvist