Brad if I remember right, they rent (not sure of the price) out four spots a day for the wakeboarding side and four spots a day for the slalom side. Two of the four permits are for the morning and the other two is for afternoon. Then the 2 boats rotate until your pass runs out, but sometimes no one else shows up and you get it to yourself for the whole day.
I use to love riding there, it was great for training, because the way its set-up makes you ride in a tournament format.