low water vs lowtide

low water

noun
  • The location of low tide in a coastal area. 

  • The temporary situation of having little money. 

  • The lowest stage of a river. 

lowtide

noun
  • The point at which the sea level is at its lowest during any given cycle 

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