Avoid Cruise-Ship Days -- Unless you're on one of them, try to avoid visiting Raiatea when cruise ships are in port, since their passengers can monopolize all organized activities here.
Either Raiatea 4x4 (tel. 66.24.16) or Jeep Safari Raiatea (tel. 66.15.73) will take you via four-wheel-drive jeep into Raiatea's interior, including a ride up to the plateau and into the ancient crater of Mount Temehani; both stop at Taputapuatea Marae before heading back to Uturoa. These expeditions are less thrill ride and more oriented to history and culture than those on Bora Bora. I would opt for Raiatea 4*4, especially if the highly informative Ronnie Moufat is to be your guide. Each outfitter has two trips a day, requires reservations a day in advance, and charges about 4,500CFP (US$56/£28) per person.
The mountains of Tahaa have much less dramatic scenery than on Raiatea, and the island lacks the historical importance of its big sister. Consequently, safari expeditions here include visits to La Maison de Vanille (House of Vanilla; tel. 57.61.92), where visitors are informed about the cultivation and uses of vanilla (Tahaa's major product), and to a black-pearl farm. Most tours follow a four-wheel-drive trail through the mountains from Patio, on the north coast, to Haamene, in the center of the island. These invariably include a refreshment stop high on a ridge with a view over Haamene Bay. I thoroughly enjoyed my expedition guided by the energetic and engaging Roselyne Atiniu of Dave's Tours (tel. 65.62.42). You can also go with Vai Poe Tours (tel. 65.60.83). Either will pick you up at Uturoa.
If you can put together your own group (because a minimum of four persons is required), you can take a variety of lagoon excursions and see firsthand the Raiatea-Tahaa lagoon, one of the most beautiful in French Polynesia. All trips include snorkeling, and most include picnics on the motus (tiny islets) sitting on the outer reef; unlike the mainland of Raiatea and Tahaa, they have beautiful white-sand beaches. Motu Toahotu and Motu Mahena are equipped with restrooms and other facilities, for which the locals extract a 500CFP (US$6.25/£3.15) per-person entrance fee. Dave's Tours (tel. 65.62.42) will take you out from Uturoa.
Marie and Tony Tucker (she's French; he's South African) of West Coast Charters (tel. 66.45.39) offer a complete tour around Tahaa with swimming, guided snorkeling over the magnificent coral gardens next to Le Taha'a Private Island & Spa, a shark-feeding stint, a pearl-farm visit, and lunch for 8,500CFP (US$106/£54) a person. Both Marie and Tony speak fluent English as well as French.
Andrew Brotherson of Manava Excursions (tel./fax 66.28.26; email@example.com) also charges 7,500CFP (US$94/£47) per person for his all-day trips to Tahaa. They include visits to a vanilla plantation and pearl farm, a picnic on a motu, and snorkeling over the coral gardens. He also takes a boat trip up the Faaroa River and on to the Taputapuatea Marae, priced at 4,500CFP (US$56/£28) per person.
Another option is Bruno Fabre's L'Excursion Bleue (tel. 66.10.90; www.tahaa.net), whose full-day trip around Tahaa costs 9,500CFP (US$119/£60).