Indispensable Reefs

The Indispensable Reefs are a chain of three large coral atolls in the Coral Sea. They are located about 50 km (30 mi) south of Rennell Island. The chain stretches over a length of 114 km (71 mi) and its average width is 18 km (11 mi).

Administratively the Indispensable Reef belongs to the Rennell and Bellona Province of Solomon Islands. They are locally called "Goto'akau".^{[citation needed]}

The three atolls are steep-to and each encloses a large deep lagoon. They are separated by deep passages two to three km (1.2–1.9 mi) wide. The atolls of the Indispensable Reef are aligned in a NW-SE direction:^[1]

• North Reef is 18 km (11 mi) long, and up to 7 km (4.3 mi) wide. The rim of the atoll has two narrow openings in the north and northwest. The reef has a total area of 100 km² (39 sq mi), including lagoon and reef flat. There are no islets.
• Middle Reef is 51 km (32 mi) long. Little Nottingham Islet is a small islet located near the centre of the reef. Besides its main lagoon, Middle Reef has a separate smaller northern lagoon. The total area is about 300 km² (120 sq mi).
• South Reef is 21 km (13 mi) long and up to 8 km (5.0 mi) wide. It encloses a lagoon 18 to 35 metres (59 to 115 ft) deep. The total area exceeds 100 km² (39 sq mi).