Race of supernatural amphibious people native to the seas around Orkney. The men were dark of complexion and had fins which could be wrapped about them so as to look like clothes, or otherwise concealed by magic. They were fond of human women, and there are many tales of young girls being carried off from the shore by them. They travelled in boats, using oars (never sails) for propulsion. These were enchanted such that they could travel to Norway or Iceland from Orkney with just seven oarstrokes.
The Fin Folk made use of the rich fishing around Orkney, and kept fishing grounds. If a mortal fisherman strayed into these areas, he could expect to incur their wrath, and have his tackle destroyed, or a tiny hole made in his boat where it would not be seen until it was too late. Protection against such sabotage could be taken by painting a cross on the side of the boat, to ward off the heathen Fins.
The Fins loved silver, "the white money" as they called it. If a man was ever hired by a Fin, he would invariably be paid in coppers.
The women of the Fin Folk ("Fin Wives") were mermaids, and the most beautiful creatures to live on land or sea (which kinda makes you wonder why the male Fin Folk were so keen on our women... but I digress). The Orcadian mermaid differs from the typical in that instead of a fish's tail, she wore a beautiful petticoat of silver and gold, which closed over her feet when she was in the water. If a mermaid were to grip the bow of a boat and ask the state of the tide, the wrong answer had to be given. Otherwise, she had the power to pull the boat under the sea.
Mermaids were also keen to find a human husband; if they married a Fin Man, they would eventually grow old, losing their beauty and becoming a haggard Fin Wife. If they married a mortal man, they remained forever youthful and kept their dazzling looks forever.
Under the sea, the Fin Folk lived in Finfolkaheem, a city of coral. Above the sea, they lived on the lush green island of Hilda-Land (lit. 'hidden land'), which was invisible to the human eye. The island was also known as "Hether Blether", and could occasionally be seen from Rousay, off in the Atlantic.
- Muir, Tom 1998 "The Mermaid Bride, and Other Orkney Folk Tales". (Kirkwall Press, Kirkwall)