From a Tidal Wave: Each half of the wave does a Switch the Wave (ends crossrun to farthest center while centers "flip" into vacated end positions to re-form the wave). Then the center four Switch the Wave. Each half again does a Switch the Wave and the center four Switch the Wave. Finishes in another Tidal Wave.
This definition is from The Handbook of Modern Square Dancing by Jay King.
It is provided here for informational and educational purposes only.