Fly 24+ hours to Singapore or to Bali, then fly about 2 hours to Manado in Northern Sulawesi. In Manado, hire an outrigger canoe (plentiful) to take you to one of several dive-oriented islands in Bunaken bay, or dive from the mainland.
This was taken from the deck of a dive boat, but under water is equally awesome.
The waters off northern Sulawesi are the epicenter of underwater biodiversity. The waters are crystal clear, warm, and Bunaken is a large bay surrounded by 5 perfect volcanos. Breath taking would under-state the serene beauty of Bunaken