Wave
White wash
The foamy, broken, turbulent part of the wake behind the clean face; riders try to stay ahead of it in the clean pocket.
White wash (also called the wash or white water) is the aerated, broken foam that tumbles behind the wake's clean curling face. It marks the back edge of the rideable wave. A good wakesurf wave has a clean section ahead of the wash; if a rider drops too far back they sink into the white wash and lose the push.
Boat setup, particularly the use of a wake shaper, aims to clean up the wash so it doesn't crumble into the pocket and foul the wave.