This is kind of interesting. Hyperlite has installed a webcam at Radar Lake that provides a pretty good quality picture. Unfortunately, it's at the opposite end of the lake from most of the sliders, so you really can't see much if somebody is hitting one.
That being said, I just logged on and saw somebody being pulled by a PWC hit one of the sliders. Pretty cool feature, especially since it's free! http://188.8.131.52/