Aiwo Drop-Off

The Aiwo Drop-Off on Nauru's western coast is one of the most vertically dramatic walls in central Micronesia, plunging from a shallow reef crest at 4 metres into water exceeding 2,000 metres deep just a few hundred metres offshore. The wall face is split by undercuts and small cave openings at around 25 to 35 metres that shelter whitetip reef sharks resting in groups. Silvertip sharks and occasional oceanic whitetip sharks cruise the blue water off the wall during the calmer months. Current upwelling from the deep ocean brings good nutrient flow and supports large sea fans, crinoids, and black coral along the deeper sections. The western exposure means this site is best dived in the April to September window before westerly swells build; surface conditions can deteriorate quickly.