I will reiterate my motorcycle suggestion, or rent a convertible for the day and just get away from Honolulu for a day. Try to find a surfing competition, or check out some turtles.
My second suggestion is book a ride on one of the catamarans on Waikiki beach. Drinks were included the day I went. Gliding silently across the water while gazing down down through the depths of crystal clear cobalt blue sea is mesmerizing.
Honolulu is pretty crappy, IMO, so just get out of the city often if you can.