I worked and Lived in Waikiki for three years. If you’re staying in that part of town there are several local dive shops to choose from. They all go out of the Ala Wai Boat Harbor near Ala Moana. Dives are mostly Plane or Ship wrecks some on the deeper side. Vis is excellent usually 80-100’ but water can be a little chilly. If your thinking live coral reef teaming with tropicals not so much, more opportunity for larger pelagic’s. If you’re adventurous don’t miss the free diving with sharks on the North Shore. I’ve been out with Oneocean Diving a hand full of times, they are top notch, safety first, shark research professionals.
Enjoy!