Plan to explore this fantastic lagoon. If you're not diving, the best way is on a full-day excursion. The two main attractions are on the eastern and western ends of the lagoon, each at least a 1 1/2-hour boat ride away from the main island each way. That means you will spend at least 3 hours going and coming, so you will need a full day for each attraction -- and a good set of sea legs if a strong wind kicks up choppy waves on the lagoon. The tours do not operate in bad weather or really rough seas, which are more likely to occur during the austral summer months from December through March. In other words, don't be disappointed if the weather washes out your planned excursion.
Les Sables Rose (Pink Sands), on the eastern end, is a phenomenal beach laden with pink sand. It's one of French Polynesia's most picturesque beaches, and to call it deserted is an understatement. Second on my list is Lagon Bleu (Blue Lagoon), a small lagoon carved into the reef on the western edge of the big lagoon. Literally a lagoon within a lagoon, this shallow pool is full of colorful corals and plentiful sea life. Thousands of seabirds nest nearby on aptly named Ile aux Oiseaux (Bird Island). A third day here can be spent at Ile aux Récifs (Reef Island), on the south side, where erosion has created razor-sharp coral formations (be sure to bring reef shoes on this trip).
You will be able to swim and snorkel at these sites, and the boat staff will prepare a beachside lunch. These trips are not inexpensive: Plan on paying 10,000CFP to 12,000CFP (US$125-US$150/£63-£76) or more per person for a full day's outing, including lunch, soft drinks, and use of snorkeling gear. The hotels and pensions either offer their own or can arrange lagoon excursions.
A shorter alternative if you don't have that much time -- or that much spare change -- is a glass-bottom boat ride over the coral heads inside the passes. You'll see lots of fish and, if you're lucky, a shark or two. Most hotels and pensions can arrange these excursions for about 3,000CFP (US$38/£19) per person.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.