My Dad is a retired Chair Force Col. He still fly's a lot but he's not much of a water man. Give him a shout and see if he can hook you up with flights or a tour of the island.
I grew up on O'ahu in a place called Aiea, the only us city with all vowels in its name. I lived there from 1979 - 1992, I went to Radford High School and spent a brief stay at UH before I dropped out due to a surfing accident. Surfed at Pipe one day 10 - 15 foot Hawaiian size and hit the inside sandbar pretty hard. Came home that night and found out I collapsed a lung. I was told no surfing for 6 months and sat in a bed for 3 weeks.
But give my Dad a call. He might be able to hook you up.