I just got back from hawaii too. Before I went, I looked really hard for kayaking opportunities. If you can find a boat good for surf kayaking I bet it would be a lot of fun. I saw one guy out with a long fiberglass boat, and it looked like a blast. With that said, its probably a pain in the butt getting the boat stuff taken care off. Might as well get a mask/snorkel, or rent a surfboard and do the stuff that you can really do well in Hawaii. In the end I figured I would pass on kayaking as I can do that in colorado. You will have fun either way I am sure. Also it depends on which island. The only one that I found was on Oahu (go bananas). If you want more info, go to boater talk and do some searches there. Several threads in the past.