I was there a few weeks ago with my 3 yr old and 8 yr old. My 3 yr old had a blast playing in the sand! True - it does not stay together and you are unable to really build a castle, but he did not care. We put a life jacket on him and swam him out to one of the two trampoline in the ocean - he loved that too.
We did spend a fair amount of time at the pool. It is huge with lots of shallow spots for chairs that he played on too.
We did bring our own sand toys, but we forgot towels. We bought one towel at the gift shop. $22! Yikes!
They also did not charge him an entrance fee - which I thought was nice.