After taking the kids to Breakwater Beach for the past few years, I can say that the water park can stand alone as its own destination. In other words, it isn't just an "extra" while spending a week at the beech. For us, it is worth the two hour trip just to go on the slides.
First and foremost, as a parent, the small and enclosed structure gives me a sense of safety for my children. There are plenty of slides, yet they are all so close, which makes not only for less walking, but also for a more secure feeling when trying to keep tabs on multiple kids.
The park is clean. It is a bit pricey, but I like that since the price seems to make it more of a family destination. Plus the price keeps the crowds down.
The slide selection isn't up to par with some of the bigger water parks like Disney's Typhoon Lagoon, but there is certainly enough to keep kids busy all day. Adults will find the options suitable for a couple hours of fun at the very least. There are plenty of chairs for the adults, which I found great since my kids are now at the age when they can run off for a bit on their own.