Rarotonga Island. Cook Island. Polynesia. South Pacific Ocean. Diving Centre in Rarotonga: The big Fish, The Dive Center. Lagoon Dive with de Dive Center. Rarotonga (meaning 'down south') is the largest of the Cook Islands at 20 miles in circumference and is the most likely island to visit if you intend to dive in the archipelago. Its interior is virtually unpopulated and the edges of the island are fringed by sandy white beaches and coral reefs. The mountainous and rugged inland areas are and covered in rainforest, and streams make there way down the steep valleys to the sea. To travel around Rarotonga takes about one hour by car or buses depart hourly from Cook's Corner Arcade in Ararua. The coast road fully circles the island and there is another intermittent road about 500 metres further inland. It is only possible to travel across the island on foot as there are no roads. To walk across takes three to four hours, stopping at 'the Needle' where you can experience panoramic views of the island. It is possible to organise walks through travel agents, but these can be hard going for people not used to mountain walking, especially if it rains as the paths become slippery. Rarotonga lies just inside the Tropic of Capricorn, so has a tropical climate. Air temperatures range from a low of 18°C in winter (May to October) to a high of 29°C in the summer when it is also wet and humid (November to April). The capital of Rarotonga is Ararua. There are a number of villages along the coast that are very colourful and clean and the towns house plenty of restaurants, bars and cafes with seafood as a common dish. Accommodation is available in either hotels, holiday homes or in rented bungalows. The dramatic scenery of the youngest geologically speaking of the Cook Islands provides a stunning backdrop for wherever you stay. Rarotonga rises a maximum of 658 metres from sea level and is surrounded by a lagoon that extends several tens of metres to the outer reef, before dropping dramatically away to depths of over 4500 metres. The lagoon is great for snorkelling, particularly at Titikaveka. Beyond the lagoon, the reefs and drop offs that fall away to thousands of metres make great dive sites with caves, canyons and tunnels to explore. There are also some wrecks to break up the reefs, some of which have been damaged by cyclones that have hit the island. The best drop-offs are along the south coast, but the north coast sustains better coral growth. Unfortunately there has been an invasion of the destructive crown of thorns starfish, which has lead to a reduction in the amount of coral. However, a culling is taking place which is allowing the coral to fight back a little and some over fishing has lead to fishing bans in places. There is no decompression chamber on the islands, the nearest is in New Zealand, so make sure that you are carrying sufficient travel insurance.