If anyone is diving in Powell in the next month or so, remember that it's still monsoon season. There can be sudden hard, localized thunderstorms. If you're on foot in a side canyon, it can be extremely dangerous, as an unseen approaching flash flood can be 20' deep in a narrow, slot canyon. If you're a diver, the after effects in the lake end of the canyon can be zero viz, since the floodwater is more like liquified mud.
