XTC Dive Center (north end of town, across bridge, no phone, www.xtcdivecenter.com , 9 a.m.–5 p.m. daily) is a full-service dive shop that specializes in trips to Chinchorro Bank ; its acronym officially stands for “Xcalak to Chinchorro,” though the nearby ecstasy-inducing dives certainly figured into the name.
Trips to Chinchorro are US$190 per person for two tanks or US$135 per person for snorkelers, including lunch, drinks, and a hike on Cayo Centro, the main cay; multiday trips also are available.
To get to Chinchorro, it’s a 1.5-to-2-hour boat ride, which can be pretty punishing depending on conditions. You typically set out around 7 a.m. and return to port around 4:30 or 5 p.m. Dive shops usually require at least five divers or six snorkelers (or a combination of the two) and may not go for days at a time if the weather is bad (summer months are best).
Closer to home, reef dives cost US$50 for one tank, US$75 for two; equipment costs extra. Snorkel tours run US$30–55 per person depending on how long and far you go; five-hour trips include jaunts into Chetumal Bay and Bird Island, which can be fascinating, especially in January and February when the birds are most plentiful. A 10 percent tax applies to most rates.
Costa de Cocos (3 kilometers/2 miles north of town, no phone, www.costadecocos.com ) also offers diving, as does Casa Carolina (2.5 kilometers/1.6 miles north of town, U.S. tel. 610/616-3862, www.casacarolina.net ). Prices at all three shops are comparable.
Xcalak  also boasts world-class sportfishing, with huge saltwater and brackish flats where hooking into the grand slam of fly-fishing—tarpon, bonefish, and permit—is by no means impossible. Add a snook, and you’ve got a super slam. Oceanside, tarpon and barracuda abound, in addition to grouper, snapper, and others.
Costa de Cocos (3 kilometers/2 miles north of town, no phone, www.costadecocos.com ) is the area’s oldest fishing resort, with highly experienced guides and numerous magazine write-ups, including Fly Rod & Reel and Gray’s Sporting Journal. Three-to-seven-night packages include transfer to and from the airport, lodging, meals, open bar, and of course nonstop fly-fishing (US$1,770–3,970 s, US$1,370–2,995 d).
Hotel Tierra Maya (2.1 kilometers/1.3 miles north of town, toll-free U.S. tel. 800/216-1902, www.tierramaya.net ) also offers fly-fishing packages for 3–7 nights (US$1,370–3,605 s, US$770–2,099 d), though they don’t include all the perks that the Costa de Cocos packages do. The dive shops, as well as most hotels, also can arrange guided fishing tours.