Mountain Biking -- The sparse car traffic, relatively subtle rise in altitude, and abundance of off-road trails and paths make San Cristóbal an excellent place to explore on a mountain bike. Most rides begin on the 6.5km (4-mile) paved road to El Progreso. But that's where the pavement ends, and a variety of destinations are possible from there. One of the more popular rides is to El Junco . This 19km (12-mile) ride is mostly uphill on the way there, but welcomingly downhill on the way home. All the tour agencies and hotel desks in town can arrange a guided mountain-bike tour, or they can find you a bike to rent.
Kayaking -- There's some great kayaking all around San Cristóbal. You can choose to either paddle around Bahía Naufragio, or to venture farther afield. If you want to rent a kayak, check at the Hotel Orca , or with any of the tour agencies in town. Rental rates run $5 to $8 (£3.35-£5.35) per hour, or $15 to $25 (£10-£17) per day. All the tour agencies in town offer guided half- and full-day kayak trips as well.
Snorkeling & Scuba Diving -- As you'll find throughout the archipelago, the snorkeling and scuba diving out of San Cristóbal are excellent. Snorkelers often have close encounters with sea lions and sea turtles, while scuba divers frequently come across schools of hammerhead sharks, eagle rays, Galápagos sharks, and the rare whale shark. Some of the popular dive spots include Roca Ballena (Whale Rock), Isla Lobos (Sea Lion Island), Punta Pitt (Pitt Point), and the Caragua Wreck.
Chalo Tours (tel. 05/2520-953), at Española and Ignacio Hernández; and Wreck Bay Diving Center (tel. 09/4794-313; email@example.com), at Avenida Charles Darwin and Teodoro Wolf, are the two most established dive operators on the island. Rates for a two-tank dive outing, including all gear and lunch, are $100 to $150 (£67-£100). A snorkel outing, including equipment, should cost $25 to $45 (£17-£30) per person. In both cases, the higher-priced trips involve greater travel time and distance to the dive or snorkel spot.
Surfing -- San Cristóbal has the most consistent and best-developed surf spots in the Galápagos, if not the entire country. Some of the better-known breaks include La Lobería, Punta Carola, and Tango Reef. If you're a surfer, you should definitely contact the local surf association, Asociación de Surf de San Cristóbal (tel. 05/2521-345). They can help get you orientated, and even provide you with permits and transportation to breaks that are located inside protected areas or offshore from San Cristóbal. Caution: The surf here is not for beginners, and there are no surf schools, board-rental outfits, or mellow beach breaks. If you come to the Galápagos to surf, you should probably know what you're doing, and bring your own gear. If you want to sign up for a surf tour with an operator that has lots of local experience, check out Casa del Sol (www.casasol.com).
Swimming -- While you can swim in the protected harbor from Playa de Oro, I recommend taking a taxi out of town to one of the several rather spectacular beaches found on the west side of the island. Of these, Cerro Brujo and Puerto Grande are the best, although Playa Ochoa and Playa Mangelcito are also beautiful. None of these beaches are ever crowded.