1963, in reference to vehicles attached to parachute-like canopies, from first element of parachute (n.) + sail (n.). As a verb by 1970. Related: Parasailing.
Entries linking to parasail
parachute n.
"apparatus, usually in the shape of a very large umbrella, carried in an aircraft, that may allow a person or thing to drop to the surface below without injury or damage," 1784 (the year the first use of one was attempted, in Paris), from French parachute, literally "that which protects against a fall," hybrid coined by French aeronaut François Blanchard (1753-1809) from para- "defense against" (see para- (2)) + chute "a fall" (see chute).
PARACHUTE, a kind of large and strong umbrella, contrived to break a person's fall from an airballoon, should any accident happen to the balloon at a high elevation. ["Supplement to the Encyclopaedia or Dictionary of Arts and Sciences," Philadelphia, 1803]
sail n.
"piece of shaped cloth spread so as to catch the wind and cause a vessel to move in water," Old English segl "sail, veil, curtain," from Proto-Germanic *seglom (source also of Old Saxon, Swedish segel, Old Norse segl, Old Frisian seil, Dutch zeil, Old High German segal, German Segel), of obscure origin with no known cognates outside Germanic (Irish seol, Welsh hwyl "sail" are Germanic loan-words). In some sources (Klein, OED) referred to PIE root *sek- "to cut," as if meaning "a cut piece of cloth."
As "a single ship or vessel" by 1510s. To take the wind out of (someone's) sails (1888) is to deprive (someone) of the means of progress, especially by sudden and unexpected action, "as by one vessel sailing between the wind and another vessel" ["The Encyclopaedic Dictionary," 1888].