The Collaborative International Dictionary of English v.0.48:

Yachting \Yacht"ing\, n.
   Sailing for pleasure in a yacht.
   [1913 Webster]

WordNet (r) 3.0 (2006):

yachting
    n 1: water travel for pleasure [syn: boating, yachting]

Moby Thesaurus II by Grady Ward, 1.0:

21 Moby Thesaurus words for "yachting":
   boating, canoeing, circumnavigation, coasting, cruising,
   gunkholing, motorboating, navigability, navigating, navigation,
   passage-making, periplus, rowing, sailing, sculling, sea travel,
   seafaring, steaming, travel by water, voyaging, water travel