In Oct 2003, DH, DD & I had dinner at Ohanas, which we really enjoyed. After dinner, when the waiter brought us our bill, he encouraged us to head down to the beach to watch the fireworks. When he brought us our change, he even told us how to get to the beach. We did walk down to watch the fireworks, and there were very few people on the beach.
Last summer, again, my family had dinner at Ohanas, and once again, we were encouraged to stick around for the fireworks! Our waiter told us that we'd get a great view from the beach. We headed out, and played around on the hammock and even enjoyed swinging on the swing. We didn't see any signs on the beach, but to be honest, we weren't looking for signs either. Both times, our waiters told us we could go. And, I have to say, I did hear him telling other people around our table about the excellent view down on the beach. (We didn't stay for the fireworks though; we caught the monorail back and as we got to the bus stops, the fireworks started!)
We didn't know we were doing wrong. We knew we couldn't swim in the pools, but didn't think anything about sitting around on the beach. (Not that it makes any difference, but both times we were there, there were not that many people on the beach. There were still lots of chairs.)