A maelstrom is a very powerful whirlpool; a large, swirling body of water. The power of tidal whirlpools tends to be exaggerated by laymen. There are virtually no stories of large ships ever being sucked into a maelstrom, although smaller craft are in danger and tsunami generated maelstroms may even threaten larger crafts. Tales like those by Paul the Deacon, Jules Verne and Edgar Allan Poe are entirely fictional.
One of the earliest uses of the Scandinavian word was by Edgar Allan Poe in his story “A Descent into the Maelstrom” (1841). In turn, the Nordic word is derived from the Dutch maelstrom, modern spelling maalstroom, from malen (to grind) and stroom (stream), to form the meaning grinding current or literally “mill-stream”, in the sense of milling (grinding) grain.