The record breaking waves at Chimelong Spaceship’s main tank are turned on randomly throughout the day, not only during shows. The whales enjoy the waves very much, and the trainers let them express themselves in the waves (surfing, fast swimming, sliding, etc.). So far, the whales have not been trained to do any particular behaviors with the waves, mostly with regard to the safety of the whales and staff.
Sources: https://www.facebook.com/macaodaily/posts/pfbid0tpwTLwYTwRe2nNxoi6op8CP55aqvdteEYYcoYHY7SXzovNpCxFhiQtXfHpfjAwVvl and http://xhslink.com/pPmVNw and http://xhslink.com/cNuVNw