We were there Monday. We got in around 8:15 AM. I had a small wait for the plunge, which I did first thing. When we left at 3 the park was still open to new admissions. The lines were reasonable all day, allowing that after lunch, as the lines were building, we were in the wave pools.
My opinions on the park? The Dolphin Plunge is a great idea, but at least for me it wasn't worth it. The tube rides near the plunge were great. The toboggan style ride and the two family rafts rides were excellent as well. The wave pools don't measure up to Typhoon Lagoon.
Paul