I was recently on Hilton Head Island beach for a week in early August. We had our dog, Ozzie, with us, and we kept him leashed. There were many people there, and we only walked him after 5 p.m.
During the week, we observed numerous dogs off leash on the beach during the prohibited hours. And after 5 p.m., many dogs were loose and not under voice control.
A young woman was running, and her dog went after a family walking on the beach. They were clearly frightened, as was I, that they would be bitten. She finally got her dog under control and jogged off.
The biggest problem with dogs is the stupidity of the owners. I have yet to see someone given a citation for breaking the rules posted, and they are broken often.