Go early in the week if you can. People start there vacations on the weekend (mostly) and focus on the parks (mostly) sunday through Wednesday, then start looking for something else to do. If you arrive on Saturday, I'd do theme park on Sunday a water park on Monday, a theme park on Tuesday, and the other water park on Wednesday. Even if you only go for half the day and to a theme park the other half, the waterparks break up the touring and allow some muscles to rest while you use others. The waterparks are by no mean a break though, unless you only do the lazy river and hang out in a lounge chair.