We usually travel to Maui so car rental there is a definite. We are thinking of spending 3 or 4 days on Oahu staying on Waikiki beach. We do want to go to Pearl Harbor but the rest of the time we will probably stay on Waikiki. Is a car a necessity on Oahu or can we just cab it? I see cabs from airport approx $30, but what about a cab to Pearl Harbor? What is the distance?