We can provide no better description of Ha'apai than Lonely Planet's guide:
"Sprinkled across the kingdom's central waters, the Ha'apai Group is an idyllic South Pacific paradise -low coral islands, white reefs and kilometres of deserted white beaches fringed with coconuts palms. Traditional culture is not something you pay an entry fee to experience in Ha'apai - it's all around unexploited and alive. Of its 62 islands, 45 are inhabited. Divers enter a whole new realm exploring blackened walls laden with colourful corals while pelagic rise from depth nearby. Whale-watching is largely an incidental experience while travelling between islands, though low visitor numbers allow you to view the mammals without the crowds. A kayaking adventure through the islands is one of the most exhilarating adventured the world offers."