Hawaii

Malaekahana Beach on the North East shore of Oahu, near the town of Laie. Beautiful, uncrowded. Good swimming.
Dig Me Beach, in Kapiolani Park at the Diamond Head end of Waikiki, between the Natatorium and the first of the Diamond Head hotels. Good swimming, not as crowded as the rest of Waikiki, mostly local people, many quite exceptionally beautiful.
The Halekulani Hotel House-Without—Key bar for great cocktails and hula dancing at sunset (Stay there if you can afford it-easily the best hotel in Waikiki.

Where ever you go, be careful of petty thievery. Locals leave nothing in their car when going to the beach, leave all their valuables at home and keep an eye on their stuff when at the beach. Like so many other places, Hawaii has a drug fueled homelessness crisis that translates into lawlessness.