open sea vs surf

open sea

noun
  • That part of the sea out of sight of land. 

  • A sea open to all nations, i.e. not a mare clausum. 

surf

noun
  • Waves that break on an ocean shoreline. 

  • A dance popular in the 1960s in which the movements of a surfboard rider are mimicked. 

  • The bottom of a drain. 

  • An instance or session of riding a surfboard in the surf. 

verb
  • To bodysurf; to swim in the surf at a beach. 

  • To surf at a specified place. 

  • To browse the Internet, television, etc. 

  • To ride a wave on a surfboard; to pursue or take part in the sport of surfing. 

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