Source : Webster's Revised Unabridged Dictionary (1913)

Waterman \Wa"ter*man\, n.; pl. {Watermen}.
   1. A man who plies for hire on rivers, lakes, or canals, or
      in harbors, in distinction from a seaman who is engaged on
      the high seas; a man who manages fresh-water craft; a
      boatman; a ferryman.

   2. An attendant on cab stands, etc., who supplies water to
      the horses. [Eng.] --Dickens.

   3. A water demon. --Tylor.

Source : WordNet®

waterman
     n : someone who drives or rides in a boat [syn: {boatman}, {boater}]