Tongatapu has a magnificent lagoon and reef, with five marine reserves and two island parks protected by government legislation.
Ha'apai Group - great reef geography. There are caves, canyons, caverns and tunnels with vertical walls, fast flowing passes and colourful coral gardens. Hard corals dominate the reefs but there are also gorgonian fans and soft corals to be found.
Vava'u Group - excellent drift dives along walls and drop offs, as well as the interesting wreck of a copra steamer right off Neiafu. There are also some good coral reefs with lots of fire coral and several areas with large gorgonian fan grottos. Visibility is usually excellent, often exceeding 40m.
For better readability of the table, pass into the landscape mode.
Tonga is in the south Pacific Ocean comprising 169 islands, 96 of them inhabited, stretching over a distance of about 800 kilometres (500 miles). The islands lie south of Samoa and are about a third of the way between New Zealand and Hawaii.
Tonga is the only surviving monarchy among the island nations of the Pacific Ocean, The islands are also known as the Friendly Islands because of the friendly reception accorded to Captain Cook on his first visit in 1773.
Only 45 of its islands of the 171 islands are inhabited. About two thirds of the islands' inhabitants live on the island of Tongatapu in the south. The other main islands are the Vava'u Group a little further south, the Ha'apai Group in the middle and Niuas in the far north.