   
  To bring up the DepthSounder from the instrument room, left click
  on it or press 'd'. It is the instrument at bottom center of the instr-
  ument room screen.
  The butons work as follows:
  COLOR  Gives a color parabola display which indicates the gradient
         average for the reading region. A high slope parabola with
         mostly red-brown color indicates a large difference between
         the shallowest depth and deepest depth in the reading area.
         Keypress 'c'.
  GRAPH  A visual indication of the shallowness (top line(s)) and deepness
         (bottom line(s)) of the area. Magnitude emphasized by vertical
         length of the lines.
         Keypress 'g'.
  DATA   Top figure shows how many fathoms down the deepest portions in 
         the area are. The middle reading is depth in feet directly 
         below the ship. Bottom figure the fathom depth of the shallowest
         figures returned.
         Keypress 'd'.
  R      Take a reading. 
         Keypress 'r'.
  Like all instruments, the EXIT button or an 'e' keypress "returns" you
  to the instrument room.






