Puerto Rico  has a slew of tour operators offering a variety of adventures that span the spectrum from guided city walks to deep-sea dives to mountain-climbing hikes. All tour companies require reservations.
Legends of Puerto Rico (Old San Juan, 787/605-9060, fax 787/764-2354, info [at] legendsofpr [dot] com, www.legendsofpr.com ) offers a variety of daytime and nighttime walking tours of Old San Juan  that revolve around a variety of topics from history, pirate legends, and crafts. It also offers a Modern San Juan  tour and hiking tours of the karst region, El Yunque , and mangrove forests.
Acampa (1211 Ave. Piñero, San Juan, 787/706-0695, info [at] acampapr [dot] com, www.acampapr.com ) offers a large selection of hiking, rappelling, and rock-climbing adventure tours throughout the island. Sights include San Cristóbal Cañon , Río Tanamá, El Yunque , Toro Negro Forest , Mona Island, and Caja de Muerto Island. Acampa also sells and rents camping, hiking, and mountaineering gear at its store in San Juan .
AdvenTours (787/889-0251 or 787/831-6447, www.adventourspr.com ) is an ecotourism operator offering hiking, kayaking, and biking tours out of Mayagüez, Rincón, Luquillo , and Vieques . Sights include a coffee plantation, El Yunque , archaeological sites, and more.
Aquatica Dive and Surf (Carr. 110, km 10, Gate 5, Ramey, Aguadilla, 787/890-6071, Mon.–Sat. 10 a.m.–5:30 p.m., Sun. 9 a.m.– 3 p.m., aquatica [at] caribe [dot] net, http://premium.caribe.net/~aquatica ) has mountain-bike tours of the west coast as well as dive and snorkel trips and surf instruction.
Expediciones Palenque (787/823-4354 or 787/306-4382, info [at] expedicionespalenque [dot] com, www.expedicionespalenque.com ) offers a variety of daylong spelunking, rappelling, body-rafting, and base-jumping tours in the Cordillera Central . This is strictly for adventure travelers in good physical condition. Sights include Río Tanamá, Yuyú Cave, Tunnel Cave, and Arch Cave.
San Cristóbal Hiking Tour (P.O. Box 678, Barranquitas, PR 00794, 787/857-2094 or 787/647-3402, walimai [at] hotmail [dot] com, http://barranquitaspr.net/viajes/english.htm ) offers a variety of weekend excursions in San Cristóbal Cañon  from moderate hiking and biking tours to extreme rappelling and mountaineering tours. It also offers tours to Bosque Estatal Toro Negro and other natural sights in the area.
Adventure Tourmarine (Carr. 102, Joyuda, 787/375-2625 or 787/255-2525, tourmarinepr [at] yahoo [dot] com, www.tourmarinepr.com ) offers snorkeling, dive, and fishing tours along the west coast, as well as two-day camping trips to Mona Island.
Aventuras Tierra Adentro (787/766-0470, www.aventuraspr.com ) offers daylong adventure expeditions into the wild. Saturdays are devoted to rock climbing, rappelling, and body- rafting in a canyon. Sundays are reserved for hiking, rappelling, and swimming in the Río Camuy cave system. This adventure is for the physically fit and adventurous.
East Island Excursions (Puerto Del Rey Marina, Fajardo, 877/937-4386 or 787/860- 3434, fax 787/860-1656, www.eastwindcats.com ) offers sailing and snorkel trips aboard a 62-foot sailing catamaran with a glass bottom and a slide, a 65-foot power catamaran, or a 45-foot catamaran. Excursions are available to Vieques , Culebra , Culebrita, and St. Thomas .
Encantos Ecotours Suroeste (Placita La Parguera, 787/808-0005 or 787/272-0005, fax 787/789-1730) offers nighttime kayak tours of Bahía Fosforescente in La Parguera, as well as snorkeling, bike, and hiking tours in Bosque Estatal de Guánica .
Las Tortugas Adventures (4 Calle La Puntilla, San Juan, 787/725-5169, info [at] kayak-pr [dot] com, www.kayak-pr.com ) offers a variety of half- and full-day snorkel and kayak tours on the east coast, launching from Bahía Las Croabas in Fajardo . Tours include Las Cabezas de San Juan in Fajardo , the bioluminescent lagoon, mangrove forest in Piñones , and excursions to Cayo Icacos, Cayo Diablo, and Monkey Island.
Mona Aquatics (Calle José de Diego, next to Club Naútico, Boquerón, 787/851-2185, fax 787/254-0604, www.monaaquatics.com ) offers dive tours, sunset cruises, and nighttime tours of Bahía Fosforescente. It also provides overnight camping and diving trips to Mona Island.
Sea Ventures Dive Center (www.divepuertorico.com; Carr. 3, km 51.2, Fajardo, 787/863-3483 or 800/739-3483, www.divefajardo.com; Copamarina Beach Resort, Carr. 333, km 6.5, Guánica, 877/348-3267 or 800/468-4553, www.divecopamarina.com; and 110 Harbour Dr., Palmas del Mar, Humacao, 787/781-8086 or 787/739-3483, www.divepalmasdelmar.com ) has three locations from which it offers a variety of diving and snorkeling tours along the east and southwestern coasts. Destinations include Vieques , Culebra , and Cayo Santiago (Monkey Island) in Naguabo .
Taíno Divers (Black Eagle Marina, Carr. 413, 787/823-6429, www.tainodivers.com , daily 9 a.m.–6 p.m.) offers daily snorkeling, dive, and whale-watching tours along the west coast. Fishing charters are also available.
Caribbean Fly Fishing (61 Calle Orquideas, Esperanza, Vieques, 787/741-1337 or 787/450- 3744, flyfish [at] coqui [dot] net, www.caribbeanflyfishingco.com ) offers inshore kingfish, amberjack, barracuda, pompano, and tarpon fishing trips on a 21-foot Ranger bay boat.
Light Tackle Adventure (Boquerón pier, Cabo Rojo, 787/849-1430 or 787/547-7380, www.lighttackleadventure.8k.com ) specializes in light-tackle and fly-fishing excursions. It also provides kayak tours of the Cabo Rojo salt flats, Boquerón Bay, Joyuda, and La Parguera. Bird-watching tours on the Cabo Rojo salt flats are also available.
Tropical Fishing Charters (Sea Lovers Marina, Fajardo, 787/379-4461, www.tropicalfishingcharters.com ) offers year-round big-game fishing, specializing in blue marlin, from May to October.
Aquatica Dive and Surf (Carr. 110, km 10, Gate 5, Ramey, Aguadilla, 787/890-6071, Mon.–Sat. 10 a.m.–5:30 p.m., Sun. 9 a.m.–3 p.m., aquatica [at] caribe [dot] net, http://premium.caribe.net/~aquatica ) offers surfing instruction as well as mountain-bike tours and dive and snorkeling trips. They are accredited by the National Surf Schools and Instructors Association.
WOW Surfing School (San Juan, 787/955-6059, info [at] gosurfpr [dot] com, www.gosurfpr.com ) was founded by international surf champion William “Chino” Sue-A-Quan. Accredited by the National Surf Schools and Instructors Association, it offers instruction at two locations: Isla Verde just east of the Ritz Carlton, and Playa Escambron by Hotel Normandie in Puerta de Tierra between Condado and Old San Juan .
Rincón Surf School (787/823-0610, info [at] rinconsurfschool [dot] com, www.rinconsurfschool.com ) conducts a surf school for beginners and experienced surfers looking to up their game. You can get a 2.5-hour private lesson, or between one and five full days of class instruction. It also offers a Surf & Yoga Retreat for women.
Surf 787 Summer Camp (Carr. 115, Rincón, 787/448-0968 or 949/547-6340, www.surf787.com ) offers accommodations and surf instruction for adults only from December through April. From June through September, children ages 11–17 can attend the kid’s day and overnight surf camp featuring a full day of surf instruction, three meals a day, and evening activities.