Book a boat or scuba-diving tour and sail out to this unique atoll off the Maui coast, which is teeming with seabirds and marine life, including humpback whales.

Molokini is a partially-submerged volcanic crater, creating a picturesque crescent-shaped atoll off the Maui coast. It’s thought ethnic Hawaiians used to paddle to Molokini to fish and harvest the eggs of seabirds. Today, the established Molokini Island Preserve is all about protecting nature, and visitors are invited to enjoy its crystal-clear waters. Tour operators can only moor off the coast of Molokini, because visitors are not allowed to set foot on the island itself.Molokini may cover only 18 acres (7.2 hectares), but the atoll is home to an abundance of wildlife, mainly found on and in the water. The clear turquoise waters around Molokini are inhabited by more than 250 marine species, even though there is now less coral than there used to be. Molokini is also a protected seabird sanctuary. The atoll’s steep sides and curved shape form sheltered conditions for divers. Book a guided dive trip, don some scuba gear and jump in to see colorful parrotfish, yellow tang, butterfly fish, reef sharks and the inquisitive Moorish idol. Fish feel far less threatened by humans here and are less skittish than normal.If you don’t dive, you can still see Molokini’s underwater world by booking one of the glass-bottomed-boat tours that bring you right over the reef. Take your binoculars and see if you can spot some of the local birdlife. You might see wedge-tailed shearwaters and Bulwer's petrels, among other special species. From late December to early May, Molokini becomes an excellent spot for sighting the humpback whales, or “kohola” as the Hawaiians call these massive mammals. If you are lucky, you can hear the males “sing” while you are underwater, or spot a mother and calf breaching the surface.Molokini sits 3 miles (4.8 kilometers) off Maui’s southwestern coast. There is no opportunity to stay overnight. Tours on catamarans, rafts and yachts leave daily from Maalaea Harbor, Makena, Lahaina and Kihei, and often include a meal on board. It is recommended to leave early before the afternoon winds pick up. The “Windy Island” is best avoided when the sea is choppy.