You can dive at Pulmo  year-round, but the best conditions are in summer and early fall, when water temperatures exceed 26°C and visibility exceeds 30 meters.
Guided drift diving is the norm here. Divers board a panga boat at the beach, zip over to the morning’s dive site, and roll backward into the water to begin the dive. While divers drift with the current along the reef below, the boat captain follows the bubbles on the surface.
The sides of the reef are jam-packed with colorful marine life. Green moray eels poke their heads out of rocky crevices, schools of tropical fish dart here and there, and the occasional sea turtle cruises by. It only takes a few dives to begin to recognize the telltale pile of shells in front of an octopus’s den or the antennae of a spiny lobster hiding in a cave.
Besides the natural reefs, the wreck of a tuna boat called El Vencedor has evolved into an artificial reef. Dive boats also take groups to El Islote, a lone rock on the southern side of the bay, and to a sea lion colony near Bahía de los Frailes .
Three dive centers, located within 100 meters of each other, run guided tours from Cabo Pulmo. In the village center, the Cabo Pulmo Beach Resort (El Camino Rural Costero, tel. 612/141-0884 or -0885, U.S. tel./fax 562/366-0398, www.cabopulmo.com ) operates a PADI-certified dive center with two boats, well-maintained gear, and experienced, professional dive guides. A two-tank boat dive costs US$75 and an equipment rental package is US$20 with a boat dive.
You do not need to be a guest of the resort to snorkel or dive with the shop. The dive center often hosts groups of day-trippers from resorts in the Cabo San Lucas area . These dives tend to be more crowded with novice divers. Call ahead to check the schedule if you want to do more advanced dives. Snorkeling tours are US$40 with gear, and single kayaks rent for US$35 a day.
Cabo Pulmo Divers (tel. 624/130-0235, cell tel. 612/157-3381, www.cabopulmodivers.com ) is another option, located in the Castro family complex, next to the Miscellanea Market. Rates at both are comparable to those at the Cabo Pulmo Beach Resort.
Next to La Palapa restaurant, in a blue building with a marine-life mural painted on its side, is Cabo Pulmo Eco Adventures (no tel.). Owner Juanito offers snorkel trips for US$35 and kayak rentals by the hour or day, and can arrange taxi service to La Sirenita beach. Juanito is very knowledgeable, bilingual, and the only person in town who can arrange trips to the nearby waterfall and hot springs.
The dive operators are also happy to arrange boat trips for non-divers interested in touring the bay, Playa La Sirenita, and the sea lion colony.
Newcomer Cabo Pulmo Water Sports (tel. 624/130-0367 www.cabopulmowatersports.com ) offers dive trips and gear rental at competitive rates. It can also arrange fishing trips with local fishermen.
Commercial fishing and sportfishing are no longer permitted anywhere in Bahía Pulmo. Panga boats that launch from Pulmo have to go beyond the national marine park limit (8 km from shore) before putting in lines. On land, you have to travel about eight kilometers north or south of Pulmo proper to fish from shore. Kiki and Paco Castro offer half-day (US$180) and full-day (US$260) tours in their super-pangas, including gear and bait. Tuna and dorado are common offshore catches. Inquire at Cabo Pulmo Divers (www.cabopulmodivers.com ) behind the La Palapa beachfront restaurant.