snorkel vs water pipe

snorkel

noun
  • A hollow tube, held in the mouth, or mounted on and opening into a diving mask, used by swimmers for breathing underwater. 

  • A snorkel parka. 

  • A retractable tube fitted in diesel-engine submarines to allow sufficient ventilation that the engines may be used at periscope depth. 

verb
  • To use a snorkel. 

water pipe

noun
  • A device for smoking, such as a hookah or bong, in which the smoke is drawn through a container of water before inhaling. 

  • A pipe that is a conduit for water; an essential element of plumbing. 

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