pilotage vs yachting

pilotage

noun
  • The use of landmarks to guide a vessel or aircraft to its destination. 

  • The occupation of a pilot. 

  • The fee paid to a pilot. 

yachting

noun
  • A physical activity involving boats, be it racing sailing boats, cruising to distant shores, or day-sailing along a coast. 

How often have the words pilotage and yachting occurred in a corpus of books? (source: Google Ngram Viewer )