This is a spectacular place, but only once you find the more secluded spots along it.
Boulder Beach is the main big beach when you enter the area coming from Hoover Dam. When we went there, the mix of dark sand, small bits of trash, and the wind-whipped water made it unappealing.
However, a drive north and east along the upper portion of Boulder Basin completely changed my opinion. Make sure to pull off at the random stops and take a walk around. Its really spectacular at sunset, with the light and shadow making the most of the tonal spectrum of the rocks in the area.
Could I swim here? Possibly, but only during summers peak and from a boat lazily bobbing somewhere in the middle.
A must-see.