The Collaborative International Dictionary of English v.0.48:

Yachtsman \Yachts"man\ (y[o^]ts"man), n.; pl. Yachtsmen
   (y[o^]ts"men).
   One who owns or sails a yacht; a yachter.
   [1913 Webster]

WordNet (r) 3.0 (2006):

yachtsman
    n 1: a person who owns or sails a yacht [syn: yachtsman,
         yachtswoman]

Moby Thesaurus II by Grady Ward, 1.0:

18 Moby Thesaurus words for "yachtsman":
   bargee, bargeman, barger, boat-handler, boater, boatman, boatsman,
   ferrier, ferryman, galley slave, gondolier, lighterman, oar,
   oarsman, punter, rower, waterman, yachter