The island is popular with snorkelers and divers alike. The center of the island shoots up into a number of mountain peaks. The best viewing spot over the island is from Belvedere Lookout. Moorea is just one option. You can also head to Raiatea for canoe trips on the Faaroa River, the only navigable river in the islands.
Participants observe a divemaster cutting tuna as the reef sharks torpedo through for the food.
Though it's not much further than the flight to Hawaii, Tahiti receives the same amount of tourists in one year that Hawaii draws in 10 days, which means it is not only far less commercialized, but has retained more of its indigenous culture. Tahiti's rainy season extends from January to March, but it is not all that rainy even then. There may be downpours everyday for 10 minutes to an hour, but the sun usually makes its way out again. There is more availability of places during this season, though the rates are not drastically lower. The most popular time to go is during the Heiva festival in July, which is like an Olympics between the islands, with dance competitions, sporting events, and fruit-carrying contests.