It’s unfair to decipher an entire culture based on surmise and one shy diver’s wide eyes, but I am going to do it anyhow because we Westerners are rule breakers, and the gracious people of Japan, well, they are not.

We’ve just finished finning beneath the waters off Gishippu Island. A stone in the East China Sea, Gishippu is part of the lovely Kerama Islands chain. Less than 20 miles off the bustling shore of Naha — Okinawa’s capital and home to 320,000 — the Keramas possess more than a hint of Jurassic Park; several islands rise shark-finlike from the blue-green tropical waters, and many are uninhabited. As with most of Okinawa, the Keramas are a wildly popular dive destination among Japanese divers, and virtually unheard of outside Japan. On this dive, at a shallow reef called Tamana Farm, we see green sea turtles, an aquarium of anemone fish and a pair of mating cowry shells with delicate eggs that resemble opaque teardrops.

Japan is second only to the United States in number of certified divers. It’s true there are heaps of people in Japan — roughly 127 million — so the pool is vast, but that only partly explains the Japanese infatuation with the undersea realm.

Tamana Farm is beautiful, with its healthy reef and hovering life, but what I remember most as I clamber back onto the boat are the saucer eyes of a young Japanese diver.

Rocking in the sunshine, I feel the familiar giddiness every diver knows. We have returned from a wilderness, a taste of something untamed — in a land of rules, something tantalizingly illicit and wholly without stricture.

Back on the boat, the diver’s face is impassive. She keeps to herself, glancing at me only once — the briefest look, but it’s enough to tell me we both understand.

Watching Vs. Observing

Let’s dispense with the differences quickly, because frankly, in the end, they don’t really matter.

Yes, Japanese divers and diving are different. Japanese divers cling to their guides and their buddies like well-heeled remoras. During my week exploring Okinawa’s isles, I traveled and dove with a boisterous group of Americans infused with an enthusiasm that occasionally saw them stray from both buddy and guide. More than once the lot of us surfaced to polite reprimand (Please. We want more attention from you). The Japanese are also detail oriented. Returning to the dock after a day of diving, the Western diver’s line of questioning is succinct: Where can one find a hot meal accompanied by appropriate beverages? Returning to the dock, Japanese divers settle immediately into a study session that would humble members of the RAND think tank.

“Japanese divers might spend an hour and a half on their dive log,” explains Miho Yamazaki, the Bluefield Dive Shop guide who introduced us to the Keramas. “Japanese people are very inquisitive. They write down all the fish names. What’s that? What’s that? What’s that? They pay very close attention.” Miho smiles warmly and, I thought, a trifle wryly. Later she would e-mail me a list of the fish we had seen on our Keramas dives. “It’s very different,” she said, “watching versus observing.”

Watching versus observing — I liked this. I liked this very much.

More Tahiti Than Tokyo

While exploring Okinawa’s wondrous isles I worked to observe many things, above and below the water. What I observed, first and foremost, is that Okinawa is not Japan. Japan stretches more than 1,500 miles from north to south, more than 5,000 islands in all. Okinawa prefecture — think of a prefecture as a state — rests at the southern end of the string of 160 islands, about two-thirds of them uninhabited, closer in spirit and climate to Tahiti than they are to Tokyo. The average year-round temperature in Okinawa is 72 degrees F, but it’s not just the thermometer that’s different. Away from Naha, much of Okinawa remains quiet and rural — focused on fishing, farming and, as one resident put it, “the growing of the cows.” On mainland Japan, family alcoves display honorary swords; in Okinawa, the alcove is more apt to house a sanshin, a musical instrument that resembles a banjo with three strings. You might see Okinawans as flower children, minus the free love and hallucinogens. On Okinawa, even the cherry blossoms are brighter pink.

Perhaps they are only striving to enhance your stay. I have traveled the world and experienced graciousness in many corners, but if there is a place politer than Okinawa, I will eat my BCD. Imagine a world where everyone graduates from cotillion summa cum laude. At times all the bowing made me feel like a bobblehead on amphetamines, but it was inspirational too. So was the charming, nearly childlike honesty. Yes, I was humbly informed, Okinawa has between 260 and 400 dive shops (depending on whom you talk to) available to service divers. Yes, the water is tropical, often with visibility stretching beyond 130 feet. Yes, there are mantas, schooling hammerheads, whale sharks, humpback whales and wrecks. But the Okinawa dive operators I met were equally quick to reveal their shortcomings. Yes, I was told, there were dive shops with English-speaking staff, but there were plenty more whose staff spoke only Japanese. This did not seem unreasonable to me, given that 95 percent of Okinawa’s tourists are Japanese, but there was apology nonetheless.

“Okinawa has been a little behind the rest of the dive world,” said Miho, bowing slightly. “We are a bit undiscovered.”

In this the wise diver hears not a drawback, but the hum of potential.

There and Back Again

Our trip, appropriately, was one of island hopping, from the main island of Okinawa to Yonaguni Island, roughly 300 miles southwest, and back again. It’s easy to travel among Okinawa’s islands: Japan might be shy on the surface, but beneath that veneer it is ruthlessly efficient. You can fly Japan Transocean Air from Tokyo and Naha to the southern dive islands of Ishigaki — famous for mantas off Ishizaki Cape between April and November — and Yonaguni (more on Yonaguni in a moment). Modern ferries also fan out to many islands. There is reason for this convenient infrastructure — the Okinawa islands are no secret to Japanese tourists and divers. Tropical water and reams of sea life — the powerful Kuroshio current carries warm water north, allowing for coral reefs where reefs shouldn’t be, and ferrying a plethora of sea life too — would seem a klaxon call for the world’s divers, but to date it is falling on deaf ears. When we disembarked at tiny Yonaguni airport, we were the only Europeans in the terminal. A tiny boy stared at me as if the top of my head had erupted in flames. I handed him my surfboard key chain. He returned a perfect small bow.

Borrowing a page from the Okinawan people, I will confess I much prefer small places to large, and so I loved tiny, 11-square mile Yonaguni from my first salt-laden breath. The island is home to three small mazelike towns huddled against the water. The rest of the island is a green mosaic of sugar-cane fields, dripping jungle and grassy swards grazed by the tiny Yonaguni horse, which is only slightly larger than the Atlas moth, the world’s largest moth and Yonaguni’s other signature animal. The majority of street signs point to lookouts, and there are some stunners: craggy cliffs falling into blue-green seas. You would have to be dizzy (Memai ga shimasu) not to see that Yonaguni swims in aji (character). When I picked up a brochure urging me to enhance my visit by “learning how to make homely and delicious traditional meals,” I knew I was home.

Yonaguni is Ha Te (the very far end), Japan’s westernmost inhabited island. Situated as it is, the island benefits from the full brunt of the Kuroshio current. Fishermen know Yonaguni’s waters for swordfish and tuna. Divers — at least Japanese divers — know Yonaguni for giant cuttlefish, barracuda and schools of 100-plus hammerheads, the latter massing in winter to breed.

This being early October, we missed the hammerheads, but no matter. Yonaguni is also famous for its mysterious underwater ruins, mysterious in that no one knows what they really are. What is known is that they were discovered by local fisherman Kihachiro Aratake in 1987 while Aratake was diving for hammerheads.

A Mammoth Mystery Below

“When I first saw it, I had goosebumps and feel strange wondering why something like this exists underwater,” Aratake told a crew from the History Channel’s History’s Mysteries. I know this because he showed us the video one night in his guesthouse, Hotel Irifune Bamboo Villa. Aratake served us a lavish meal of shrimp, sashimi and other seafood delicacies — the sort of gracious hospitality we experienced throughout our trip — and quietly watched a video he had no doubt seen a hundred times.

In the video various experts sniped at each other.

“It appears to be a huge ritual religious area that predates the Egyptian pyramids by 5,000 years, making it the oldest structure in the world, forcing a possible revision of history,” said one.

“Just because it looks like history, doesn’t mean it is,” carped another.

The argument boiled down to this: Some eight stories high and 500 feet long, was the structure man-made or geological? Since none of the experts could reach a conclusion, when the video ended I asked Aratake himself.

Aratake is built much like his island, square and stolid, and possessed of a stern gaze. But when our translator relayed my question, his eyes assumed a warm light, his answer producing agreeable nods among the Japanese speakers at our table.

The translator turned to me.

“Everything is so calculated, and even all the angles so perfect. Everything is so beautiful, whether it’s natural or man-made.”

I knew exactly what Aratake meant, because we had been on the ruins that morning. Aratake runs his own dive outfit, Sa-wes Yonaguni, and he took us out himself.

The ruins are 15 minutes from Yonaguni’s harbor. The seas were mildly rough. The tops of the ruins are only about 20 feet beneath the surface; in the shallows we swept back and forth over the strange stone shapes like neoprene metal detectors. The day was overcast, throwing shadows into the water. Underwater, the breaking waves made dark, roiling storm clouds.

It was the perfect atmosphere for something mysterious, and mysterious it was. As Aratake said, everywhere you turned the stone was cleft at sharp angles: here something like an arch, there something very much like steps. There were waist-high passageways and conical borings in the rock; passing over the borings was like staring down into a throat. Geologic or no, there was something decidedly altarlike about the structure. I’m not casting a vote either way, but staring at the vast, smoky blue structure it was easy to sense something bigger than man. I finned to a quiet, current-free spot at the foot of a sheer wall and went to my knees, bowing in gratitude for the chance to once again witness something beyond the everyday pale.

Making our way back to the harbor, I didn’t join in my companions’ discussion of dinner. In my mind I swam about the ruins — observing, not watching — etching them in my memory as finely as man or the elements had.

“There’s Stuff Everywhere”

We returned to Naha for a last set of dives. We dove with Reef Encounters, a very American outfit based in Chatan just outside central Naha. “We’re not going to babysit you,” said smiling shop owner Doug Bennett.

Bennett knows Okinawa’s waters — he’s lived here for 20 years and run Reef Encounters for 16 — and what he knows, and continues to discover, excites him. Okinawa’s signature wreck dive is the USS Emmons, a destroyer resting in about 140 feet of water off Motobu Peninsula, but the Emmons is the tip of the iceberg. A few days before our arrival, Bennett and his crew had found the wreck of the USS Longshaw, a 376-foot destroyer, and Bennett told me there was more on the immediate horizon.

“Six possible sonar hits,” he beamed, as we motored off Naha’s jumbled skyline. “The more wrecks I find, the more amazed I am. There’s stuff everywhere.”

Okinawa’s plethora of wrecks comes as no surprise. From April through June 1945, the Battle of Okinawa raged above, the largest amphibious assault in the Pacific War. By Bennett’s estimate, some 1,300 vessels litter an eight-mile stretch of coast. What’s less obvious, according to Bennett, is that the Japanese do not seek out wrecks, and in many instances avoid them. Some of the reasons are complicated – spiritual beliefs included – but some are sadly simple. Dive the Emmons and you will see the outline of a kamikaze plane that crashed through its hull. To Western divers this is a curiosity; to certain Japanese divers, it’s something more.

When I asked Bluefield’s Miho Yamazaki about the Japanese reluctance to dive and ferret out wrecks, she spoke quietly.

“My grandfather’s brother was a kamikaze pilot,” she said. “When I go on the wreck, it is different for me.”

Diving with Reef Encounters on our last day, we descended to an unidentified transport barge dubbed simply the Naha Wreck. The corroded wheelhouse rested in mossy silence. Juvenile toby fish hid in the folds of a sea fan. I observed the Old World funneling away, the new one staking its claim. It was another privileged view of a special place.

It’s a secret every diver shares. Below there is no language barrier, no cultural abyss. You observe it clearly in a young girl’s single shy glance, and an impassive face that lights suddenly into a wide smile.

Must-Do Topside

• Visit the reconstructed castle of Shuri-Jo. Built in the 14th century, the hilltop castle served as the administrative center and royal residence of the Ryukyu kingdom until the 19th century. Today it offers a look at the finest Far Eastern architecture and art; outside, on clear days, Shuri-Jo affords a terrific view of Naha city and the distant Kerama Islands.
• Okinawa is champuru, a mix of many cultures. One of the best places to witness (and taste) this mix is the Makishi Kousetsu Ichiba, the Naha central market. The small alleys around the market are lined with stand-up-style shops where you can sample everything from fresh tempura to goya juice. Also on the main island, visit Churaumi Aquarium — the world’s fourth largest — and Ryukyu Mura, a cultural village displaying and selling Okinawan crafts and artifacts. Nature lovers should head for the outer islands. Iriomote-Jima is almost completely covered in jungle and mangrove; Yakushima is one of Japan’s favorite outdoor playgrounds (post play, soak in an onsen hot spring); and the beaches of the Kerama Islands are white-sand beautiful and within easy ferry distance of Naha.

Local Flavor

Okinawa is an amalgam of cultures, and so is the food. Be sure to sample Soki Soba, pork spare rib cooked in soy sauce, sugar and awamori (Okinawan liquor), served in a tasty soup with lots of noodles. Also don’t miss goya-champuru, a stir-fry of signature bitter melon, pork and shima-dofu (island tofu). Awamori purportedly helps prevent heart attacks, and you’ll have good fun doing so.

Bring Back

Kariyushi wear is the new wave of clothing. Think Hawaiian aloha shirts but designed using original Okinawan motifs. The highest quality shirts sometimes use textiles dyed with sugar cane and banana leaf.

The Guide to Okinawa

Average water temp 85˚F in summer, 71˚F in winter What to wear skin or 2 mm shorty in summer, 3 to 5 mm fullsuit in winter Average viz 100 feet and up When to go year-round, though typhoons can strike between July and October; early spring into late June, and then late fall (around Thanksgiving) are best.

Must Dive

• Yonaguni Ruins (Yonaguni Island) Geologic or man-made? Who cares — the massive eight-story structure with what appears to be stairs, arches and passages will stop your pulse either way.
• Irizaki Point (Yonaguni Island) In winter months, schools of hammerheads gather off the west coast of Yonaguni island to give birth. Local operators claim if you dive here two days in a row during this window you’re guaranteed sharks.
• Ishizaki Manta Scramble (Ishigaki Island) Between April and November (but particularly from June through October), swooping mantas gather off Ishizaki Cape on the island’s west coast. The dive is immensely popular with the Japanese, but the mantas’ beauty helps you forget the crowds.
• Manza Dream Hole (main island of Okinawa) Off Okinawa’s west coast, the hole begins at about 20 feet and opens up to a large chamber spinning with schools of fish, sometimes in the thousands. You’ll also fin through a curtain of fish at the exit, some 85 feet down.
• Zampa Point (main island) A wall that plunges more than 100 feet, complete with caves, swim-throughs, large fan corals (which favor the mild currents) and pygmy seahorses.