We have booked our car rentals for each port. When you get off of the ship the car rental agencies are normally there waiting for you and they will shuttle you to the agency to pick up your car. In Kona you can rent a car from Dollar rental and just walk across the street to the hotel to get the car, the only problem is drop off they are only open till noon, if you drop off at the airport there is a 50.00 charge.
I found the best prices as Budget in Hilo, Maui and Kauai and Dollar for Ohau and Kona. I put the local phone number of each agency in my cell phone already in case I need to call.
We have done this twice before and never had any problems. This is the best way to see each Island, go to your local library and get a book on each island to plan out your day -
If you go to the Hawaii chamber of commerce website you can request free travel planners for each island, inside you will see the location of where the ship ports.
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