Wiktionary
wave pool
n. A swimming pool in which there are artificially generated, reasonably large waves, similar to the ocean's.
Wikipedia
Wave pool
A wave pool is a swimming pool in which there are artificially generated, reasonably large waves, similar to those of the ocean. Wave pools are often a major feature of water parks. Sunway Lagoon Water Park in Malaysia is home to the world's largest outdoor wave pool, and Siam Park (Tenerife) is home to the biggest man made waves (about 3 meters (9.8 ft)) in the world.