Are you getting a rental car? If not, I highly recommend one. Not just for Pearl Harbor, you can go into HNL for dinner or go to the North Shore, Pineapple Plantation, etc. Someone told me that the Marriott (I think the name is Marriott) next door to Aulani has a Hertz rental service. But I think for what they may charge for a one day rental, you'd be better off getting a rental car upon landing. If you do Pearl Harbor on your own, get up early....very early. Probably have to even if you did a tour. Parking is limited and you want to get there before the buses and ahead of HNL traffic.