Shore excursions in Tahiti are often about the island's underwater wonders and marine creatures, however, explorations into the interior of the islands via 4x4 vehicles are also very popular. Each island is ringed by stunning coral reefs, and the lagoons within are incredibly clear for snorkeling. Far from ordinary, some snorkel tours offer experiences such as feeding sharks and swimming with stingrays. Scuba diving outside the reefs is superb. For the adventurous, one of the most thrilling excursions is circling Bora Bora by Wave-runner. By comparison, many shore excursions in Australia and New Zealand are tame city and countryside bus tours. Australia tours are generally more urban and focus on culture and history. No one wants to leave without personally greeting the country's unique wildlife, so at least one excursion that includes a visit with kangaroos, koala bears, wombats, and platypus is a must for most cruisers. While tours in New Zealand include city historic and cultural sites, those that get out into the scenic countryside reward you with off-the-beaten-track experiences that can include wildlife sightings amid native forests rich with botanical and geological features. But more exhilarating adventure tours are also common. From Christchurch, a daring whitewater rafting expedition through Rangitata Gorge includes two sections of Class-5 white water. More sedate and thoroughly entertaining is an introduction to the traditions and culture of the Maori people. A highlight is the performance of the haka, a war dance designed to frighten enemies.