What is world's biggest single structure built by living organism? The Great Barrier Reef of course. This is the center of a truly amazing part of the scuba diving world. From whale shark encounters in Ningaloo Reef to relaxed tropical diving 6000 miles away in Tahiti, the region of Oceania has an incredible array of diving on offer.

Pristine reefs and their inhabitants are the attractions in Papua New Guinea, the Solomon Islands, and Palau, while an astonishing array of World War II wrecks create a wreck diver's paradise in Truk Lagoon, Micronesia. Vanuatu combines all the joys of reef diving with a truly mind-boggling wreck - the President Coolidge. You can dive with a bizarre collection of tropical fish in cold water at one of Jacques Cousteau's favorite dive destinations, the Poor Knights Islands in New Zealand, or if sharks are more your thing head for the warm waters of Fiji that are renowned for their incredible shark dives.

It's been hard to narrow this area down to just ten choices and I'm sure I've left out some favorites in doing so. Let us know which is your favorite (of which you'd most like to visit) and if your favorite isn't listed leave a comment or stop by the forum. Voting is still open on the South-East Asia, Central America & Mexico, and North America polls.