A wave pool is a swimming pool with a mechanism which creates waves in the water. The experience of being in a wave pool is supposed to be similar to swimming in the ocean. However, wave pools tend to have very regular waves with routine heights and predictable patterns, in contrast with the much less reliable ocean. This should be kept in mind when transitioning from swimming in a wave pool to swimming in the ocean. The earliest wave pools date to the 1940s in the United States, and the concept has since spread widely across the world.
Wave pools can be divided into small wave pools, and big wave pools. Small wave pools have much smaller, gentler waves, making them suitable for children and the elderly, while big wave pools have larger waves which can be a bit more dangerous. In both cases, a wave pool is less safe than a traditional swimming pool, which means that having a lifeguard on duty is very important, to ensure that any swimmers in distress are promptly assisted.
The mechanism for a small wave pool can work in a number of ways. One of the simplest involves simply directing a steady flow of air at the water to generate ripples. Slightly larger waves can be created with the use of a paddlewheel or waterfall which churns up the water, generating waves. The mechanism for the wave pool is often hidden inside a water feature in the pool, so that swimmers are not endangered by the moving parts.
In a big wave pool, the most effective way to create big waves is simply to dump a huge volume of water in one end of the pool. As the water is poured into the pool, it displaces the water that was already there, creating waves. A channel which runs along the side of the pool collects the water, shunting it into a holding tank. Classically, the holding tank is designed to open when a certain water level has been reached, starting the wave process all over again. Other big wave pools use accordion-like systems to create pressure, which generates waves.
Swimming in a wave pool can be enjoyable, and it can also help people condition themselves. Waves create more resistance than passive water, encouraging swimmers to work a little harder. A wave pool can also help a swimmer prepare for changing water levels in the ocean, as ocean waves can be disorienting for people who have never experienced them.