Oahu, never did any diving there. Your first time there? Take a bus tour around the island. Let them drive and tell you all you need to know. Check out the north shore, great beaches. If you go to the big island, to dive, Pacific Rim Divers (PRD). Patrice is the owner/dive guide. Awesome service, great boat, (6 divers, Max.) I have been on ten trips with them, never a disappointment. Tell them the guy with good "mammal Karma" sent you. Maui, great beaches, check out Lahina for night life and tee shirts. Use ProDiver Maui, "Valet diving", again great boat, nice people, Nitrox,HP 100`s if requested. And if you are experienced (good boyancy control), the back wall of Molokini Crater is a must, several times if you can. Takes your breath away,,,, for a second anyway!! Kauai, Poipu Beach is the only area to stay. Check out the "Grand Canyon of the Pacific" Wialea Canyon. I dove with "bubbles below" not impressed. There are other outfitters on the island. Enjoy