Molokini, Hawaii,USA:

Molokini is a crescent-shaped, partially submerged volcanic crater which forms a small islet located in Alalakeiki Channel between the islands of Maui and Kahoʻolawe, part of Maui County in Hawaiʻi. It has an area of 23 acres (93,169 m2), a diameter of about 0.4 miles (0.6 km), and is located about 2.5 miles  west of Makena State Park and south of Maʻalaea Bay. It is a popular tourist destination for scuba diving, snuba and snorkeling. The islet is a Hawaiʻi State Seabird Sanctuary.Molokini's crescent shape protects divers from waves and the channel's powerful currents. However, experienced scuba divers will also drift dive off the 300 feet (91 m) sheer outer wall, using the channel currents to carry them along. The crater houses a lush reef with excellent visibility as deep as 150 feet (46 m). Molokini is home to about 250 species of fish, many endemic (see Ecology below). The best conditions occur in early morning. Because Molokini attracts many boats, the Hawaii State Division of Boating and Recreation established mooring buoys and "Day Use Mooring Rules" for Molokini to protect against damage from dropped anchors. Its popularity has led many water-sport guides to lament that overcrowding has made the experience less attractive.

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