"motorboat that glides on the surface of water," 1895, coined by U.S. engineer Harvey D. Williams ["Sibley Journal of Engineering," Cornell University, vol. x, p.81]; from hydro- + ending from airplane.
by 1908, "to skim the surface of water by use of hydroplanes," from hydroplane (n.). Meaning "skid on a thin layer of water" (especially of automobile tires) first recorded 1962, properly aquaplane (itself from 1961 in this sense). Related: Hydroplaned; hydroplaning.
the designer of marine aircraft demonstrated his newest hydroplane
the museum houses a replica of the jet hydroplane that broke the record