CANCUN, Mexico—Taking a boat out from Cancun is like visiting an aquatic Disneyland for adults. Along a 25-kilometer coastal mainland stretch of luxury hotels, there’s parasailing, jet skiing and a “pirate boat” where tourists eat surf and turf while watching a Captain Jack Sparrow type perform on stage. Eight kilometers offshore, near Isla Mujeres, divers and snorkelers flood the reef—often with the unfortunate consequence of breaking pieces of coral, bleeding sunscreen toxic to wildlife and otherwise stressing a delicate ecosystem.

Five years ago, desperate to give relief to one of the most heavily used coral reefs on the continent, a group of conservationists and artists teamed up to create an alternative to draw the tourists away. Today the underwater museum they created at a sandy shore just short of the Manchones Reef, off Isla Mujeres, showcases a collection of 200 beautiful humanlike statues. It has become an important attraction and is successfully transforming into habitat for local marine life.

The idea for an underwater sculpture garden came to Jaime Gonzalez, director of the Isla Mujeres National Park in Cancun, in 2005 after he saw how 87,000 tourists every year were literally loving the reefs to death. That year he had tried dropping “reef balls”—spherical artificial reefs—which people could perhaps visit instead.

The tour operators were not impressed, recalls Roberto Diaz, then-president of the Cancun Nautical Association that represents divers in the area, and they told Gonzalez so. “He didn’t like my comments,” Diaz says. “We have to bring tourists here. There was nothing to see. There were no fish. Just big balls that are empty—just horrible.”

Gonzalez, frustrated and disappointed, considered banning divers from the reef, but Diaz says it would have meant years in court. So rather than escalating an already tense situation, Gonzalez sought an alternative. He found Jason Taylor, a British underwater sculptor who had built a few underwater sculptures in Grenada. “A lot of research has been done about artificial reefs, and they require a lot of resources and a lot of research and a lot of maintenance,” Taylor says. Scientists have sunk cinderblocks, old tires, ships and even train cars. But most are an eyesore before algae, then corals and sponges can populate them successionally.

Taylor’s sculptures near Manchones Reef, however, were a hit. Their ghostly shapes perfectly complemented the silent blue sea. Diaz immediately began raising funds. (So far it costs $12,000 to create and install each statue.) Ironically, they were soon so popular that tour operators complained when algae moved in.

Again Gonzalez compromised. He cleaned half of the statues, using his bare hands and steel wool, and let the rest continue on their way. As he cleaned, fish would hover behind his shoulder, waiting for him to expose urchins snacking on the algae that they would then eat. Without urchins to eat it, the algae just came back. But on the rest, their urchins intact, another layer of calcium-laying organisms grew underneath the algae and now represent beautiful maturing mini reefs. In some cases sponges moved in on specific spots, such as a statue’s lips, giving the impression of lipstick. “What I never expected were the sponges,” Taylor says. “Because the sculptures are placed in an open area where there’s lots of current, the sponges are able to filter nutrients from the water. So you are seeing these amazing bright yellow, pink, red, blue—all these different types of amazing sponges.”

The installation has also attracted other scientists and artists. Five Mexican sculptors now contribute to the growing installation, and a U.S. artist is designing an iron sculpture that will, with the help of an electric current, grow a calcium “biorock” shell around it. Another sculpture of a body covered in ears houses electronic equipment that is part of a nascent network—by Heather Spence, a marine biologist with Michelle’s Earth Foundation—devised to record underwater background noise. Spence is part of a growing community who think that sound could be used to estimate the population dynamics of marine life. “We’re actually documenting the formation of a reef by listening to that process. And that’s something that hasn’t been done before,” she says.

Today, the museum’s 470 or so statues are advertised on banners across Cancun. Universities in Mexico are studying how algae, sponges and corals colonize the figures, plus how they affect traffic to Manchones. Local politicians have flocked in to share credit for its success, and a dry version of one exhibit is being installed at a local mall.

It’s hard to know exactly what impact the museum has had on Manchones Reef. Around Taylor’s Grenada installation, which is much smaller, tourism has skyrocketed (an unexpected side effect) but roughly half the tourists have been diverted to the statues. Preliminary results seem to look about the same in Cancun, but the data isn’t available yet.

So I went to Cancun to see for myself. It was midday when we finally got out on the crystal blue water with about a dozen divers. Among the passengers, only two were certified divers, the rest were beginners. One group visited the Manchones Reef but most of the half-dozen groups on the water were at the museum. Once in the water one first-time diver had trouble staying down and kicked up a fair amount of sand (which can smother coral). But the instructor easily grabbed the divers and kept them from floating off, and the sand settled safely, hundreds of yards from Manchones Reef.

Back on shore, Taylor, Gonzalez and Diaz have more big plans. They want to build 10,000 statues at the site in 10 years—that would be more than the number of Terracotta Army sculptures excavated near Xi’an, China. Taylor envisions an underwater exhibit on human evolution—Egyptians, Greeks, Aztecs—all the way to present times (although with a budget of $8 million, this goal may be difficult to achieve). He is also designing his biggest creation yet: a giant statue that appears to be holding up the ocean. “If we can find a nice alternative—something that can attract tourists, and not just for a day, but two or three,” Gonzalez says, “maybe in the future we can close these resources completely.”