A monofin is a type of swimfin typically used in underwater sports such as finswimming, free-diving and underwater orienteering. It consists of a single or linked surfaces attached to both of the dive
A freediver using a monofin
Herbert Nitsch wearing a monofin at the Cyprus BIOS 2004 Freediving Open Classic
Monofin made in 1969 by Franco Pavone in Bologna
In folklore, a mermaid is an aquatic creature with the head and upper body of a female human and the tail of a fish. Mermaids appear in the folklore of many cultures worldwide, including Europe, Latin
Monofin
…to both of the diver's feet, emulating the fluke of Cetaceans like whales or porpoises. Even though the diver's appearance might be reminiscent of a mermaid or merman, monofin swimming is not the same as mermaiding. The arrival of the monofin in the early 1970s led to the breaking of all finswimming world…
John William Waterhouse A Mermaid
The Fisherman and the Syren, by Frederic Leighton, c. 1856–1858
Siren and onocentaur.―Bern Physiologus. Berner Burgerbibliothek, Cod. 281, fol. 13v
Siren in a Second Family bestiary―British Library MS Add. 11283, fol. 20v.