When you say they've had luck on other islands, do you mean luck on other Hawaiian islands and now it's time to try Oahu and Waikiki, or are you talking "islands" in general? Diving in Waikiki is not like diving elsewhere in the state, even on Oahu itself... there's a lot more going for Oahu than just Waikiki (Oahu does have some good wrecks and I've heard Makaha caverns is a pretty good dive) and there's better overall diving on Maui and the Big Island than Oahu from what I've heard.... I just think it's a bit odd that the diving options would be Waikiki or off to Florida unless they've already done the other diving available in Hawaii.