BUNAKEN'S REEFS, among the richest in the world—they host around 70 genera of coral, while Hawaii's have 17—ring the island in a range of undersea cliffs that plunge to incredible depths. These near-vertical walls, which draw cool deep-sea water, helped protect Bunaken from the devastating 1997–98 El Niño, which killed some of the world's best reefs. The combination of high walls and varied corals attracts an abundance of both reef and pelagic animals, from Spanish dancers to blue marlin.

It's my final day on Bunaken, and still no ghost pipefish. With Vitro Tumpia, my guide, I hover at 30 feet along the edge of a wall called Likuan. If there's no feeling of vertigo, it's because the depths below us are impossible to comprehend. If the ocean were drained, we'd be poised like hawks, hovering over the rim of the Grand Canyon.

As a last-ditch effort, Tumpia suggests a night dive. After the sun drops, we motor out to the "house" reef, less than 100 yards from Froggies' lights. Incredibly, the water feels even warmer at night; it's like plunging into God's private Jacuzzi. We descend slowly, our dive lights blooming over the corals. By night, the reef is as resplendent as Times Square—there's a whole new set of creatures, some in their finery, others with claws. A big sponge crab scuttles by, carrying its ungainly camouflage on its back; a lobster hides in a tiny cave, its long antennae testing our scent. Parrot fish shelter in place, sleeping in cocoons of saliva.

My air-pressure needle drops gradually. It's time to let go of my pipefish obsession and get Zen about the experience. That won't be so hard to do—the truth is, diving in Bunaken is better than any Yankees game: Every moment is a great moment.

It's a noble sentiment that I almost believe. But my reverie is broken by the thunking of Tumpia tapping his tank. I swim toward him, and there they are: a pair of ghost pipefish, two inches long, hanging like red-and-white ornaments near the mouth of a feather star. We stare at them, shining our lights away from their eyes and watching their ethereal dance. How, I wonder, do they see us? We loom beside them large and ungainly, like balloons in a Macy's Thanksgiving Day Parade.

That night, after a dessert of ripe snake fruit, the zoology books come out. The other divers blink at me dismissively. "See anything this evening?"

"Just a few Dromidiopsis edwardsi. A Scarus bleekeri. Oh—and a couple of absolutely gorgeous Solenostomus paradoxus, hanging out near a crinoid."

They raise their eyebrows, nodding silently. Muller kicks me under the table, grinning like the seventh dwarf.