When you think of South Sea, you think of paradise. The natural beauties of Oceania''s island world, scattered far across the South Pacific and divided into the cutural areas of Polynesia, Micronesia and Melanesia, are overwhelming. But besides lonel y palm islands, ever-warm lagoons and colourful coral reefs, there are also more rugged beauties such as the volcanic-islands of Marquesas, wheere beaches are rare.