We put ashore at Tagus Cove in the bronze light of late afternoon, scraping the bow of our Zodiac onto the hard black sand beach.  A few yards inland, a mountain rises up from the sand, buttressed with thick ridges. It looks raw, freshly created from the earth.

I have studied local maps and know I will need a steady uphill climb to give me a perspective on the landscape that I couldn’t realize at sea level.  The spine of one ridge is fluted, and there is a narrow trail hidden inside of it.  I follow it up atop a thin patina of red soil, iron and magnesium and sulfur once spit out of the volcano as ash and smoke and fire, now finely ground to dust.  The path, which is at first a steep heart-pumping natural stairway of small boulders, becomes more of a gentle incline as it goes higher.

It leads me above a thousand feet, up to where finely woven nests of ground finches hang from the bare limbs of the ghostly palo santo trees.  Looking down, I see that the cove, in the shape of a perfect half moon, is what remains of a volcanic crater. Time and tide collapsed the seaward wall of its colder long ago, and now the ocean fills the geological bowl where magma once roiled. I have walked up the rim of the other half of the crater that still remains.

I’m in the Galapagos, 600 miles offshore South America in the Pacific, the lone writer aboard a research ship full of marine scientists.  These islands straddle the Equator, and common sense would have them tropical and warm. But they are also washed with bewildering crosscurrents, like the Humboldt, which transports ice-cold water up from the Antarctic.  Wayward penguins once rode this current northward, and today they have become part of a menagerie of animals and plants, which after drifting, flying or swimming here, have been singularly molded by the isolation of the place. They include giant land tortoises with shells shaped by how they feed on the individual islands where they live; iguanas that have learned to swim underwater and graze algae from boulders; a finch that hunts insects like a woodpecker, except that it holds a twig in its beak and uses it as a tool. Entire families and classes seem to have changed anatomically, just by the act of being in a place my shipmates call the “cradle of evolution.” The scientists are here hoping for new discoveries, ways of describing a genus or a species that has never been examined before. I am here for discovery, too, except my logic is more inexact, a childlike sense of anticipation rooted somewhere deeply in my gut.

In some vague way, this place is a reflection of how we are all fashioned by our own realities. Here in the Galapagos, without the nonsense of civilization to muddle up the point, it is just more evident.

This is an odd piece of geography, where cold water meets warm sky and mist sometimes rises up unexpectedly, clouding everything in a pale blur.  I have been on the deck of our research ship at dawn by myself, and could not see more than a few yards in any direction. Once, a whale surfaced and splashed, maybe fifty feet away from me, fully hidden in a vacuum that was white, cool. As I stood there alone on the stern, I heard it release the air from its massive lungs in one extended monstrous breath. It sounded as if the entire sea itself was exhaling, expelling a million years worth of memory in a single giant burst of spray and power and light. The mist gradually parted, perhaps from the force of the whale’s exhalation, and I could see a portion of its immense body, dark and barnacled like the bottom of a ship, moving deliberately through the water. The moment seemed vaguely hallucinogenic, and I felt as if I were there but also somewhere else, my lonely soul like the disembodied spindrift of the whale’s breath. And then as suddenly as it had surfaced, the great cetacean had vanished, dissolving back into the water without a sound.  I was still alone on the deck, and with me in the white were only the sounds of the gulls, shrieking at each other, and then, even that was too was gone. No wonder the early Spanish, not sure if these islands were real or imagined, first mapped them as ”Encantada,” enchanted.

And now, up here on the edge of this collapsed volcano, I realize the ridge I’ve been hiking has taken me to the top of the rim shared by Tagus and the wholly intact bowl of an adjacent caldera, one that sprawls out for a few hundred meters inland.  A young naturalist named Charles Darwin made this same hike after putting ashore here at Isla Isabella in the HMS Beagle in 1835.  For Darwin, these islands offered a rare glimpse into the beginning of the world itself. The experience was so powerful that it changed him from a creationist; but the dissonance was palatable—it took him the rest of his life to work up the courage to finally admit that animals and plants alter to adapt to their place on earth.

The inland volcano cradles a small, sullen lake at the bottom of its bowl.  It is a steep walk-crawl down the sides, and I have no reason to go there. But Darwin was here in the heat of the midday sun and, without a canteen, hoped the lake might quench his thirst. He scrambled down to the bottom of the caldera with no hesitation. But when he cupped his hands to drink, he was startled to find the water was saltier than the ocean itself. All was not lost: Mapmakers named the crater “Volcan Darwin” in his honor.

Seaward, I look down on the broken and submerged crater of Tagus through my binoculars and see a half dozen green turtles mounting the shells of each other, frothing the turquoise sea in their passion.  As I watch, each raises its ancient, armored head up out of the water, gulping air in sheer turtle bliss.  I have seen other sea turtles underwater during my month here in this isolated archipelago.  And each time I have been struck by their primitive grace, the way they glide like huge stout hawks through the water, the glint of another millennium shining in their eyes.

I start to hike back down to the craggy shore of Tagus just as the sun dips below the volcanic peak of nearby Isla Fernandina. The air out here, free from mainland dust, is remarkably clear, unencumbered with the residue of human conceits. On the horizon, the curvature of the earth falls away on both sides, and guilelessly, I catch myself wondering why the ocean itself doesn’t simply drain away.  In the cusp of the bright scarlet light between late afternoon and evening, I see Jupiter and Venus burning atop each other next to a crescent moon, watch the brightest meteor I have ever seen streak a long white trail past them all. It seems to be checking off one more day of life, Darwin’s creationist God still at work, busy with time-keeping, dutiful and sure.

After dark, back on the ship that brought me here, I put on scuba gear and with ichthyologist John McCosker, slip under the black water at the edge of the cove. Here, with our dive lights turned off, we settle slowly to the bottom at 80 feet, flashes of bioluminescence sparkling in front of my mask like the fireflies I used to see as a kid in country fields. We are here in these islands to capture new specimens of fish, and with nearly 40 percent of marine life found no where else on earth, our chances are always good.  Fish sleep too, and they hide very well, so it helps to look deep and at night.

I look for McCosker, but he seems to have been swallowed up by the ebony sea. Finally, he exhales, and the upwelling of his air exhaust tears through the plankton over his head, outlining each tiny bubble in a rim of blue-green. It is cold down here, and even in a thick wetsuit, subtle waves of chill move through my body and my teeth chatter inside my regulator. Briefly, we turn on our lights and shine them under the rocky ledges, down into places where the molten lava flow from the craters ran so long ago.  The sea has done a magnificent job of colonizing itself over the eons, upholstering the old lava with a thick fabric of coral and worms, sponges and tiny invertebrates, all united here in their isolation from the mainland.  From under the ledge, a Port Jackson shark swims excitedly out, a slender and spotted dwarf-like creature no bigger than my arm.  As it does, it swiftly pinballs off a rock, and my light and my attention ricochets with it. I hesitate, look down and see a nudibranch the size of my little finger in a crevice just below.  Striped and iridescent, this marine slug is speciated, custom-designed for tasks we humans can barely imagine. Local Ecuadorian fisherman, in awe of its vivid strips, call it El Tigre.

We flick our lights off again, plunging us back into primal darkness.  I watch as a large discus-shaped form moves easily away from us in the water, its shell and flippers clearly outlined by the broken bioluminescence, a sizzle of muted cobalt.  It is a sea turtle, perhaps one of those I saw earlier on the surface.  It disappears and the field in front of me is filled again with flashes of bio-energy, random synapses firing in the salty wet pulp of unconsciousness.

They tell me reptiles don’t dream, having evolved long before the rest of us earned the genetic right to that sweet luxury.  But I wonder: Do they even need to, out here in an enchanted place that is still part dream itself?

Isn’t it enough to fly underwater like colossal thick-bodied birds, tiny wings of scales moving them as fast as they ever need to go? Isn’t it enough to thread their blue-green trail through the eye of the cosmos until it is hemmed shut, and the world becomes still again, volcanoes and tortoises, finches and humans, all waiting patiently to be finally born from the liquid wakefulness of the earth, of its God, of memory itself?

I blink, shaking my head, heavy now with nitrogen and visions too powerful to fully absorb. My intellect stirs, and I find it astounding that my regulator is still in my mouth, and that I have remembered to breath. Time has shifted somehow, and I inhale slowly, ever slowly, not wanting to disturb the water with my exhalations. Around me, fish I can not see softly moan, and shrimp click their tails, sounding like the muffled hum of cicadas.

I am waiting for the whale now. I think I hear her sweet night voice, calling from somewhere deep inside the black sea.

Bill Belleville is a Florida-based magazine writer, author and documentary filmmaker specializing in environmental issues. His books include River of Lakes, Deep Cuba, and the forthcoming “Sunken Cities, Sacred Cenotes and Golden Sharks: Travels of a Water-Bound Adventurer.” Visit him at Equinox Documentaries and BillBelleville.com. His magazine and newspaper credits include Sierra, Islands, Newsweek, Salon, and The Washington Post.

Top and middle photos of Isla Santiago courtesy of Dr. John McCosker, California Academy of Sciences. Bottom portrait of author courtesy of Bill Belleville.