hydrographic vs littoral

hydrographic

adj
  • Of or pertaining to hydrography. 

littoral

adj
  • Of or relating to the shore, especially the seashore. 

noun
  • The zone of a coast between high tide and low tide levels. 

  • A shore. 

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