There is a lot to do on Isla Holbox  besides lying in a hammock (though be sure to make time for that, too!), and various excursions can be arranged through your hotel, local tour operators, or done on your own. Most of Holbox’s tour operators offer the full gamut of excursions, at comparable prices.
Recommended outfits include Posada Mawimbi (Av. Igualdad on the beach, tel. 984/875-2003, www.mawimbi.net ) and Mextreme Travel (central plaza, Av. Palomino s/n, tel. 984/875-2358, www.mextreme-travel.com , 8 a.m.–11 p.m. daily).
Besides swimming with whale sharks , the best place to snorkel on Isla Holbox is Cabo Catoche, a coral reef in about 2–4 meters (6.5–13 feet) of water at the far eastern end of the island. The water isn’t as clear as in Isla Mujeres  or Cancún , but the reef here is more pristine, and the animal life more abundant, including stingrays, moray eels, nurse sharks, sea stars, conch, and myriad fish. Because it is so far from town, tour operators usually prefer to combine it with another outing, such as an island tour or a whale shark excursion.
Holbox’s steady winds and shallow, nearly waveless coastal waters make it ideal for wind sports, particularly kiteboarding and windsurfing. The strongest winds are from September to March, while July and August tend to have lighter, novice-friendly breezes.
Gabriel Olmos Aguirre (aka Gabo) is a popular and accomplished instructor offering courses at all levels through his outfit, Holbox Kiteboarding (Hotel Casa Las Tortugas, Av. Igualdad s/n, cell. tel. 984/144-2227, www.holboxkiteboarding.com ), and in association with shops elsewhere in the Riviera Maya. Instruction prices, including gear, range US$50–65 per hour (private lessons) to US$35–45 per hour (group lessons); eight-hour courses also are offered for US$430 (private) and US$300 (group), with a guarantee that you’ll be able to stand on the board by the end of it. Wakeboarding classes also are offered on those days the wind dies down (US$70/hr).
Another one-man shop, Mohicano (Av. Igualdad s/n, cell. tel. 984/115-9090, babyshark6977 [at] hotmail [dot] com) is based out of a beach cabana near Casa Sandra. Kiteboarding rates range US$70–80 per hour (private lessons) and US$47–60 per hour (group lessons). Windsurfing (US$70/two hours) and sailing (US$79/90 minutes) lessons also are offered. Rentals for all three sports can be arranged, too.
Kayaking is a great way to see the interior lagoons of Isla Holbox , and especially for spotting birds. A fun and challenging option is to hire a golf-cart taxi to drive you and your boat—balanced on the back—to the main inlet where you can put in. From there it’s possible to wend through the lagoons to the other side of the island, then paddle along the shore to the main ferry dock, passing Isla Pájaros along the way. Several shops and hotels rent kayaks (US$7–10/hr), while Andrés Limón (kayak_holbox [at] hotmail [dot] com) is a popular private guide.
Holbox has more than 30 species of birds, including herons, white and brown pelicans, double-crested cormorants, roseate spoonbills, and greater flamingos (the brightest pink of the five flamingo species). Most hotels can arrange a standard bird-watching excursion (approx US$40 pp, 3–4 hours, minimum four people), which generally includes taking a motorboat or kayaks through the mangroves to Isla Pájaros  and the flamingo nesting grounds. More specialized bird-watchers may want to contact Juan Rico Santana (tel. 984/875-2021)—he leads many of the hotel trips, but he can arrange separate, more focused trips that are tailored to your interests.
Holbox is an excellent spot for sportfishing, yet it’s still relatively unknown. A deep-sea fishing excursion costs US$250–450, depending on how long you go out. A coastal fishing tour with a local fisherman, going after smaller and more plentiful catch, lasts 4–5 hours and costs around US$100. Local tour operators, and most hotels, can help you organize either trip.
Holbox also has great fly-fishing, with 100-plus-pound giant tarpons cruising the coastal waters, and smaller juveniles plying the interior lagoons, along with snook and jack. Holbox Tarpon Club (tel. 984/875-2144, www.holboxtarponclub.com ) offers personalized tours, running US$400 per boat in the high season (6 a.m.–2 p.m., lunch included, max two anglers per boat), including all permits. Tackle can be rented on request.
Holbox has an amateur baseball team, known simply as Selección Holbox (Team Holbox). The season lasts all summer, and games against visiting teams are held most Sundays at noon at the baseball “stadium” on Avenida Benito Juárez a few blocks from the pier. It’s a popular outing for island families, who typically bring tostadas and huge bowls of homemade ceviche to go with the cold beer and soda on sale in the stands. Admission is US$1–2; bring a hat as there is little shade.