I recommend goign in early for a few hours ( maybe opening through 11 am ) .. do the water rides and the rides you really want to do .. then leave when the crowds pick up.
Come back mid afternoon/early evening .. do the other rides you want to do and the ones you want to do AGAIN !
You can enjoy the fun with less of the hassle plus you'll be fresh and ready for dinner by around 8/9 pm with a tall cocktail on the porch at Jimmy Buffets ( make reservations though !!!!! )
A perfect day !
Personally, I try to go out of high season so it's not usually an issue, but when it's busy this is the plan I use.
Hope it helps !