12. Aitutaki, Cook Islands. Aitutaki is the second largest island in the archipelago, which forms the Cook Islands in the South Pacific, between Hawaii and New Zealand. Gradually Aitutaki becomes the second tourist island in the archipelago after Rarotonga, the main island. This is due to its small population (about 2000), in connection with which it seems deserted, but its amazing beaches and waters make scuba diving and diving there unique.