Sentence:  Now and then in the lagoon you hear the leaping of a fish [...]. And above all, ceaseless like time, is the dull roar of the <WSD>breakers</WSD> on the reef. 
Meaning of the word marked with <WSD> tags:  A wave breaking into foam against the shore, or against a sandbank, or a rock or reef near the surface, considered a useful warning to ships of an underwater hazard