Our first stop on the way to Paul's Rock,Survivor Beach or Hat Island is at Tukutuku, from where legend says King Roymata was carried through caverns beneath the waves, to Hat island. The tunnels and caverns of Tukutuku were formed by the erosion of coral limestone during lower sea-levels. While they are underwater, most of the tunnels are open at the top, and you can snorkel across them. Experienced snorkellers can swim through the tunnels, by surfacing periodically in these open passages for another breath of air. Others can swim over the top. Illuminated by shafts of sunlight from overhead cracks, the interconnected caverns have an ethereal beauty. From the outside coral wall, most tunnels lead to a miniature 'elf-garden' lagoon inside the reef (see arrow).This lagoon is also accessible at high tide to snorkellers who do not wish to swim through the tunnels.

Outside the cavern system, the coral is particularly vibrant with richly coloured hydro-corals growing along the walls of the cuttings. Dugong and reef sharks are often seen. We do not normally go ashore here, as the reef is sharp and there is generally only limited access.