The water park is not that far from the rides like at Great Adventure and other parks with both types of amusementsso you will be albe to do both.
when we go we wear our suits with either a t-shirt or a sun dress to cover, and pack some dry clothes and towels. We put these into the locker by the water park as soon as we arrive.
We then do some water stuff since we are over by the water park, then go on a few rides then stop and eat something. Then we go back to the water park and maybe back to the rides again. When the park is closing we go and get our stuff out of the locker and change into dry clothes for the drive home. We don't bother drying off until we are ready to leave the park since you will dry enough to go onto rides and they don't stop you if your clothing is wet.