open sea vs shipwreck

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. 

shipwreck

noun
  • A ship that has sunk or run aground so that it is no longer seaworthy. 

  • An event where a ship sinks or runs aground. 

  • destruction; ruin; irretrievable loss 

verb
  • To wreck a boat through a collision or mishap. 

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