Where are all the caves??

I have walked all over a level 3 map for three separate worlds I created today.  Only settings I changed were Show Coordinates and the Caves and Cliffs toggle in experimental gameplay.  None of these worlds appear to have any cave openings, and anything that looks like it should be a cave opening is filled with water.  There are also no ravines, but there are lots of deep, water-filled caves that are sort of shaped like diagonal ravines