I spent 1000s of hours in Waikiki from one end to the other in and out of the ocean.. I know Waikiki. Anyplace there's a wall bush tree it's used as a bathroom. Hate to mention Ft DeRussy but that one the most trashed. Beer drinkers and smokers no respect  for the beach.  Would spend time at Koolina but the place is closed at night unless you want to pay for parking.