From a Line or Alamo Ring.
Designated dancers, working toward the Center of the Line, successively
  do a Partner Trade with each dancer until reaching the far end of the
  Line.  Ripple n means to Trade with a total of n dancers.
  n can include a fraction (e.g., Ripple 2 & 1/2 means to Partner Trade
  with 2 successive dancers and then 1/2 Partner Trade with the third dancer).
Notes:
- 
When Ripple is called from a 1 x 8 Line, work on each side
    unless otherwise specified.  Note however that a call such as
    Very Ends Ripple {n} where n is greater than
    3 forces the designated dancers to cross the Very Center and
    work with dancers from the other side.
- 
The caller can specify the direction toward which the designated dancers
    are to begin (e.g., Head Lady Right Ripple 2).  From an Alamo Ring,
    the direction must always be specified.
- 
If no direction is specified, the designated dancers do the first
    Trade moving toward the Center of the Line.
- 
There may be more than one designated dancer.  For example, from a
    Wave, the call could be Ends Ripple 2.
Rolling Ripple n By n (By n) [C4] (Lee Kopman 1984):
 From a Line or Alamo Ring. 
  Designated dancer Ripple the first given number;
  new dancer occupying designated dancer's original starting position Ripple
  the next given number; repeat part 2 for each additional given number.
 See also anything Like A Ripple CONCEPT [C2].