snorkel vs wade

snorkel

verb
  • To use a snorkel. 

noun
  • A snorkel parka. 

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

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

wade

verb
  • to walk through water or something that impedes progress. 

  • To enter recklessly. 

  • to progress with difficulty 

  • to walk through (water or similar impediment); to pass through by wading 

noun
  • An act of wading. 

  • A ford; a place to cross a river. 

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