life raft vs yawl

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. 

yawl

noun
  • A small ship's boat, usually rowed by four or six oars. 

  • A fore-and-aft rigged sailing vessel with two masts, main and mizzen, the mizzen stepped abaft the rudder post. 

verb
  • To cry out; to howl. 

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