Phase 1 is the intermediate wave at Boise Whitewater Park on the Boise River — the first dedicated river wave built in America, and still a benchmark for the sport. It's a playful, forgiving wave with eddies that make catching it (and bailing out of it) easy, which makes it a go-to for riders leveling up past beginner moves. The adjustable setup lets operators dial it in through the spring-to-fall season, so it stays rideable as flows shift. When Phase 1 starts feeling too mellow, Phase 2 is waiting just downstream with a much bigger step up.