PHUKET, Thailand — The coral-rich waters of the Andaman and Similan Seas off the coast of Phuket have become a mecca for scuba divers: Here awaits a treasure of diverse marine species, some of which can be found in few other places on earth.

But how many diving aficionados know anything about what they’re looking at?

Astonishingly few, according to Anne Miller and Robert Cogen of In Depth Adventures, a Phuket-based ecotourist outfit aiming to change how divers around the world view the underwater universe, through a course called Reef-World.

“With just a one-day course, you’ll learn many things that people diving for years don’t know. We’re really on the edge,” says Miller matter-of-factly. “Seasoned divers may have seen a lot and had many experiences, but they probably don’t know the basics of reef life.”

For example, how many divers know exactly why a “No Touch” diving policy may be the best one?

“Coral animals are connected, some share nervous systems or digestive systems. That’s why it’s so important not to touch coral — if you kill one animal, you can kill all the ones around it,” she explains, adding that pollution and other modern stresses make reefs particularly vulnerable.

As I contemplated spending some of my precious holiday time in the Reef-World classroom, I have to admit that I was tempted to instead head for the reef itself, or for a beach lounge-umbrella-tropical cocktail combo. But, in truth, the half-day “Introduction to Coral Reef Ecology” left me with a new appreciation for reef life, and eager for more of Reef-World.

Does the mere thought of “reef ecology” make you yawn? If so, then Reef-World comes strongly recommended. While the course content is founded in solid science, Miller has created an impressive, user-friendly package.

“We look at the reef as though it were a village on land, with different neighborhoods. Then we cover what to look for in those neighborhoods, things you can easily spot on your first visit to a reef,” she explains.

“There is the branching neighborhood, the massive neighborhood . . . one might imagine an underwater Sesame Street for adults: ‘fighting gardeners,’ like damselfish, stake out territory to farm algae, and protect it against the opportunistic, scavenging ‘street gang members,’ like wrasses,” Miller relates, mixing storytelling with marine biology. Breathtaking underwater photos by Ashley Boyd, author of the book “Thailand’s Coral Reefs,” make for a colorful learning experience.

“Street cleaners,” like sea cucumbers and urchins, and “real estate developers” like parrotfish, filled out the ecosystem drama, each serving their (ecological) function while struggling for dominance and survival just like . . . well, everyone you know.

Reef-World, the product of Miller’s collaboration with Dr. Paul Cragg of England’s National Institute of Marine Education in England, is geared toward people with no background in biology or ecology. Miller adapts the course for her very diverse clientele, from Thai school children, to experienced international divers and families or groups on holiday.

Later I ventured out to the legendary Similan islands on a five-day, live-aboard diving trip. There, with 15 fellow divers from all over the globe, I had an opportunity to observe the “more is better” mentality that most of us divers are guilty of.

“See anything?” we asked one another as we came out of the waters, which were veritably teeming with aquatic life. What we wanted to know, of course, was who’d seen the best or biggest thing — sharks, manta rays, eels, or even a whale shark.

“It’s easy to get seduced by doing deep dives, seeing lots of different things and going to lots of different places,” Miller describes, “but really, you can see just as much if you just observe one area the size of your kitchen table. If you hold still for 10 minutes or so, fish that were startled [by your arrival] come back, and you can watch them do their thing.”

The Reef-World concept, in essence, teaches a new way of diving, one that takes as much pleasure from close, educated observation as it does from the big thrills. Miller’s partner Cogen carries this philosophy on land, with In Depth Adventure’s naturalist treks, adventures to Thailand’s scenic and culturally rich north, bird-watching in the Mergui archipelago, and other personalized tours.

Hopefully, more large-scale tour groups will make use of Reef-World modules for education, and thereby help prevent the reef devastation for which they are infamous, says Miller, who is deeply involved in country-wide checks on reef health.

“Really, what we’re teaching is social responsibility for the environment — in a fun way, so that people don’t notice,” she grins.

The studies are usually balanced with a trip by longboat to some of Phuket’s excellent dive sites. Threatened with bad weather, we completed the Reef-World course with a half-day of shallow dives just off Kata Beach.

As I hovered over a patch of coral just 50 meters from the beach, in a mere 4 meters of water, I spied the micro-highlight of my diving career: two mollusks mating alongside two mating hermit crabs! No doubt it takes slow moving and close observation to win such an intimate peep into the private lives of crustacea.

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