The machinery that creates the ripple effect within the wave pool at Emerald Pointe is very simple. In a pump room below the pool, a high-speed fan blows air into a wide metal pipe, which leads to an exhaust port at the base of the volcano. In the middle of this pipe, there is a butterfly valve, a wide disc with a swiveling metal axis rod. When the rod is swiveled one way, the disc rests horizontally in the pipe, blocking the air flow. When the rod is swiveled the other way, the disc moves to a vertical position so the air can pass.
A hydraulic piston swivels the rod back and forth at regular intervals, allowing short bursts of pressurized air to flow up to the exhaust port. These air blasts blow on the water at the base of the volcano, generating the flowing ripples.
Making small waves is fairly simple with this sort of system, but it's a lot harder to form large, surfable waves. You would need an absurdly intense blast of air or a large, awfully strong plunger. Such devices would likely be inefficient, cumbersome and dangerous, so they wouldn't make for particularly good water park attractions. Instead, water parks use water-pumping wave systems. In the next couple of sections, we'll see how this sort of wave pool works.