Sounds fun, but I have two concerns. One, in the heat of summer, you run the real risk of the water parks being full by 2pm. Even if you can get in, I would expect long lines for all the slides and trouble getting a seat. Two, I'm always beat after flying. I'm not sure I would want to tackle a water park right away. Have you thought of just doing DTD at a leisurly pace and getting dinner there or at a resort hotel? Then you could make an early night of it and hit the parks bright and early the next morning. JMHO. Enjoy!