life raft vs yacht

life raft

noun
  • A usually inflatable raft carried aboard a ship or airplane, used to save lives in case the vessel has to be abandoned in an emergency on the sea. 

yacht

noun
  • Any vessel used for private, noncommercial purposes. 

  • A slick and light ship for making pleasure trips or racing on water, having sails but often motor-powered. At times used as a residence offshore on a dock. 

verb
  • To sail, voyage, or race in a yacht. 

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