During the December–April clear-weather season, veteran scuba diver and instructor Douglas Storms offers hiking, bird-watching, kayaking, snorkel and scuba adventures, and more out of his Adventure Center headquarters (Juarez 187 B, tel. 323/285-1418, www.divingbeyond.com). Off season, contact him in Sausalito, California (700 Waldo Point, Sausalito, CA 94965, U.S. tel. 415/331-7925 or 415/325-3789).

Alternatively, you might look into the services of Canadian photographer-guide John Stewart, founder of Seven Sunset Tours (www.sevensunsets.com), who works out of Casa Mañana at Playa los Cocos several miles south of San Blas. John and his staff like to lead their clients on ecofriendly tours to local villages, hidden beaches, waterfalls, bird-watching and much more.

Ecotouring in Singayta: The latter-day local growth of shrimp-pond aquaculture and the associated wildlife habitat destruction has prompted action by eco-activists in San Blas and neighboring communities, such as Singayta, five miles east of San Blas.

Singayta villagers began taking positive action around 2000. Since then, they have established a nursery for reintroduction of threatened native plants, a crocodile breeding farm, and an environmental awareness center to educate visitors and residents about the destructive reality of shrimp-pond aquaculture.

To back all this up, Singayta offers a menu of guided ecotours (www.singayta.com) for visitors. These include canoe trips into the mangrove wetland, walking tours, mountain bike rentals, donkey cart and horseback tours, and more. A restaurant also offers meals and refreshments. You might also find out more about Singayta from knowledgeable ecoleader and guide Juan “Bananas” Garcia.

Get to Singayta by car along Tepic Highway 74, about five miles (8 km) straight east of the San Blas plaza; or, by bus, from the San Blas plaza-front bus station, by one of the hourly Tepic-bound buses.