Waikīkī
The best perspective of Diamond Head and Waikiki without a helicopter. Open bar, appetizers, and the famous green flash (when conditions allow). Dolphins and humpbacks (Jan–Mar) often escort the boat.
Book through Maitai Catamaran or Na Hoku II. From $150/person for private. Board at Pier 6 near Aloha Tower or from Waikiki Beach. Open bar included on most sunset tours.
Most beautiful in clear weather; operators cancel in heavy rain or high seas.