^ thanks for the tip and I think I'll enter at opening, ride Bomb Bay and Der Stucka at first a few times and after that I'll buy an unlimited Express Pass. I buy it after Bomb Bay,... because they aren't included with the express pass and if you say that the lines at the opening aren't too long, but in the afternoon, I'm getting the Express pass later.
I won't go to Aquatica because we I'm only 2 days there (Wet'n'Wild & both Universal Parks) and I took Wet'n'Wild before Aquatica because it is more a "classic" US Waterpark and I like that. But thanks for your tips.