Molokini Crater is an uninhabited islet about four kilometres offshore from Maui, the crescent-shaped rim of a partially submerged volcanic cone. The interior water is exceptionally clear — the sheltered caldera has near-zero current and visibility regularly exceeds 30 metres — making it the most popular snorkelling and diving destination in Hawaii. Several hundred thousand people visit by boat each year.
Morning trips have the best conditions: calmer seas, better light, and fewer boats. Most operators depart from Maalaea Harbour (north of Kihei) or from Kihei Boat Ramp. A typical trip includes two to three hours in the water and returns by early afternoon. The crater rim itself is a seabird nesting area managed by the state; visitors must stay on boats or in the water — you cannot land on Molokini.