Tonga
A group of one large island and around 40-55 smaller islands in northern Tonga, world-famous for in-water encounters with migrating humpback whales and for well-developed reef and wreck diving out of Neiafu.
Vava'u consists of the main island 'Utu Vava'u plus dozens of smaller islands. From May/July to October it is one of the world's premier destinations for swimming with humpback whales that migrate here to breed, calve and nurse. It is Tonga's most developed dive region, with Tonga's best-known wreck dive, the Clan McWilliam, at about 30 m in Neiafu Harbour. Source: Wikipedia (Vava'u), tongapocketguide.com.