Diving by the Numbers
Thailand’s West Coast Isles - Part 3
ISLANDS - An International Magazine
(March / April 1996)

On land, rock climbers have a pastime called “bouldering,” in which they practice their techniques on boulders. In the Andaman Sea the bouldering was weightless and nearly effortless.

You simply pressed the button expelling air from your BCD, the inflatable vest of your Buoyancy Compensation Device, and let your weight belt take you down. It was a magic sort of bouldering – Look, Ma, no hands! – gliding with arms folded, down sheer granite walls that’s, above water, would be treacherous. You kick your fins lazily. Now and then you would have to swallow or roll your jaw to equalize the growing pressure in your ears. Otherwise no real work was required.

The granite walls were colonized by marine algae in patterns identical to those of lichen that grow on alpine granite. Only the color scheme was different, the algae purplish where the lichen was yellow-green or orange. A long crack that, in the high Sierra, would make a linear nursery for a row of whitebrak pines here gave rise to a single file of gorgonian corals in the shape of fans.

In the Sierra, lizards looked out at you from the safety of their granite clefts. In the Similans, lizardfish looked out, or peacock groupers, or red striped lionfish spreading lavish pectoral fins, or cleaner shrimp or spiny lobsters waving their antennae. In the Sierra, squirrels skittered away from you to the fair side of the trunk. In the Similans, whip coral dwarf gobies fled to the far side of the sea whip.

Now and again in my Similan bouldering, for the old times’ sake, I would use my hands. The hardness of the granite felt nostalgic and wonderful under my fingertips. In choosing handholds on terrestrial granite, I would take a hard look at the rock to make sure it was sound. In choosing handholds on submarine granite. I took a hard look to make sure the rock was really rock, and not uncanny camouflage and virulently poisonous dorsal spines of a stonefish.

The corals in Similans were not spectacularly developed, but the reef fish were abundant and diverse. I had dived only one before in the Indian Ocean, and never before in the Andaman Sea, and so many of the fish were new to me. Their shapes and habits were familiar, and I recognized all the families – angelfish, parrotfish, surgeonfish, and wrasse – but the paint jobs were almost invariably different.

In the Similans the most common sweet lips, or grunt, is the oriental sweet lips. Longitudinally striped, with bright yellow fins in a honeycomb pattern, it is one of the prettiest grunts I have seen. The fish of the coral reef are more frequently banded than striped, and the longitudinal markings of the oriental sweet lips, running against convention, catch the eyes.

The brilliant painted, closely related families of the angelfish and the butterfly fish are abundant in the Similans. The one that kept catching my eye was the red-tailed butterfly fish. It has renounced the neon blues and yellows so electric in most butterfly fish and angelfish and instead has taken up a kind of cassock of subtle but vibrant earth tones – white collar at one end, russet tail spot at the other.