In the early 1980s, scientists from the University of Baja California Sur showed up in Cabo Pulmo, a remote fishing village on the peninsula's east side. The researchers lent locals dive masks, allowing them to see the thriving reefs just off shore for the very first time. The piscators – whose fathers took to the sea before them – decided to stop fishing and advocate for the protection of the ecosystem.

A little more than a decade after the arrival of the academics, the Mexican government designated a 17,500-acre area near Cabo Pulmo as a national park. The mostly underwater park had a director with no salary, no staff, and no access to law enforcement, so villagers took it upon themselves to stop people from trolling those waters. The effort paid off big-time: When researchers from the Scripps Institution of Oceanography assessed Marine Protected Areas in the Gulf of California in 1999, only one of them had recovered from overfishing. Cabo Pulmo was thriving. The 1.72 tons of fish per acre recorded on the reef rank as some of the highest anywhere.

For divers, enjoying this stunning success story takes little effort. Walk from Cabo Pulmo Sport Center, opened by former fisherman Mario Castro in 1991, to a panga on the beach. Toss in your gear and hang on while a stripped-down Bronco with a tire lashed to its rear bumper pushes the boat into the water. A few minutes later, fall over the side and sink.

Hard corals and sea fans cover long basaltic dikes that run parallel to shore between 30 and 60 feet. Above them, schools of red snapper, yellow snapper, and jacks, numbering in the thousands, mingle with parrotfish and groupers. Octopi, rays, eels, and sea turtles are common sights and dolphins, whales, whale sharks, and enormous schools of rays are seasonal regulars.

The proximity of dive sites to shore means you can polish off two morning dips in time for a lunch of fresh fish and cold cerveza at the beachside restaurant. Siestas are never far away: Castro rents bungalows right behind his dive shop and the Baja Bungalows are a short walk away. Local outfitters also offer snorkeling with the sea lions and kayaking.

Because Cabo Pulmo's locally owned tourism infrastructure generates a higher-than-average annual per capita income, the town is one of the nicer beach communities you're likely to encounter in Mexico. There are no large developments – on shore anyway.

More information: Cabo Pulmo Sport Center charges $40 for a two-tank dive trip for a couple. Rooms at the Cabo Pulmo Beach Resort start at roughly $70 a night and Baja Bungalows run tourists $85 a night.