The first day on the island we hiked to the top of Diamond Head. Great view. Then on to the Polynesian Cultural Center (highly recommended). Next a bit of history visiting the USS Arizona Monument and the USS Missouri battleship. Then two days of diving (including a 110' reck dive... we went with Captain Brian of Dive Oahu. He and his crew were great!). Our last day we went surfing with firemen.(tad more pricy than some of the other surfing options but they are probably the safest, surfing with firemen is cool and, hey, they bring lunch.). Between times we wandered Waikiki, ate lots of great food and took in a dinner cruise.