Diving by the Numbers
Thailand’s West Coast Isles - Part 5
ISLANDS - An International Magazine
(March / April 1996)

The next morning, diving just off the point of the promontory near Ko Bon’s natural arch, we encountered schools of yellow back fusiliers and then three large manta rays. We followedone ray, whose cephalic flaps – the ventral “horns” for which mantas are sometimes called devilfish – curved inward to form a sort of open-ended barrel, helping funnel its diet of plankton into the mouth.

The ray began to roll, diving, ascending, and diving again in the slow, Sisyphean, carnival-wheel circle that mantas have been swimming for many million of years. Rolling, it showed us first its dark upper surface, blazed with white, then its pure white underside, then its dark topside again. The wings of the largest mantas are 20 feet across. This was about half that size, but it was still a very big fish.

SAILING NORTH for the Surin Islands, we made another intermediate stop, at Ko Tachai, an island as solitary and unaffiliated as Ko Bon. Diving on a reef at its southern tip, we again encountered mantas.

There were two rays this time, and the circle they swam was more horizontal than vertical. We grew great rays, flapping in their lovely, graceful, slow motion way, were still too fast for humans. Instead of chasing the rays around the circumference, we swam the diameter, making Faustian rendezvous with the devilfish time and time again.

That afternoon, while the other made a second dive at Ko Tachai, I arranged to be marooned on the island. The rubber dinghy took me into shallow water and I wadded up onto the beach. The dinghy returned to the Crescent, which motored around the point and disappeared. The sea was blue and empty. The island was all mine.

At one end of the beach, just inside the forest above the boulders of the point, Buddhist fisherman had built a small shrine. Sun, salt wind, and monsoon rains had weathered the roof of Buddha’s little house and had warped the floorboards. The bundles of burned incense sticks had lost all but a trace of their fragrance, and the other offerings were withered and old. A Torresian imperial-pigeon, luminous white in the dimness of the forest, studied me as I studied the shrine.

If any seabirds roosted in the Similans, I had not seen them, and the only birds I ever noticed working offshore were a few small flocks of terns. This absence, in shelf waters so rich, puzzled me. From the time I’d noticed a reef heron hopping along the boulders at the water’s edge, and white breasted sea eagles soaring above.

Leaving the shade of the forest, I walked barefoot across the sand. It struck me suddenly, midway down the beach, that this shore could have been almost anywhere in the tropical Indian or Pacific Oceans. The Indo-Pacific is vast – the biggest biogeographic province on earth – yet in its littoral zone, across thousands of miles of ocean, there is a remarkable sameness.

The sand of Ko Tachai was very fine, calcareous, and blindingly white in the sun. The runners of beach morning glory inscribed their calligraphy of arcs and tangents on the higher slopes of the beach, and the sand’s whiteness was punctuated at wide intervals by the dark holes of ghost crabs. Around each crab hole, piled like cannonballs on a courthouse lawn, were the round sand pellets that ghost crabs roll up in feeding.

At the crest of the beach, trimmed by the line of the highest tied, was the inevitable hedge of Scaevola. Inland was a bordering stand of beach hibiscus, the far-flung tree that Hawaiians call hau, Tongans kaute, Marshall islanders lo, and scientists Hibiscus tiliaceus. Beyond the hibiscus was a taller forest dominated by huge specimens of tropical almond, surly the most cosmopolitan of all equatorial trees. Scattered across the sandy leaf litter inside that forest were the holes of land crabs.

All this was exactly as it would have been in a thousand other archipelagos across million of square miles of the Indo-Pacific.

Natural history offered on hint of where, in all that huge realm, I stood. The only clues were in the unnatural history, the specificity in the jetsam: half-buried soft-drink bottles imprinted with Thai characters, and brown bottles of Singha beer, and worn-out plastic sandals of the type for sale in the sidewalk stalls of Phuket.

The cuttlebones lying scattered high on the beach were not diagnostic, because cuttlebone can wash up anywhere; but the big burned-out light bulbs that had come to rest alongside – the very bulbs whose brightness had lured those cuttlefish up and killed them – told me I stood on a shore of the Andaman Sea.