One gray fin, all by itself, startles a pack of surfers. It cuts the water's surface before turning sideways so that we can see its curvature and laugh, relieved that it's a dolphin. Two and three fins thrill even more, suggesting fellow travelers on this great day at San Francisco's Ocean Beach, where the Pacific wilderness booms and swirls only yards from the tightly packed homes of a major metropolis. Big blue waves roll by like miniature mountains. The wind blows up their faces, catching each crest to push a white plume arcing off the back, where sunshine paints a fleeting rainbow in the falling mist. A dolphin launches out the back of a wave in the distance, hurling itself up to shimmer in the air—another living thing at play.

"The happiness of the bee and the dolphin is to exist. For man it is to know that and to wonder at it." —Jacques-Yves Cousteau

What happens next leaves me searching for words. A good wave appears, heading toward me, presenting itself for riding. I turn my board toward the beach and start paddling, feeling the speed. I hop to my feet and fly down the 10-foot ramp, while some part of my brain registers the tip of a dolphin's fin slicing right to left across the wave face in front of me. No time for gawking: I lean the board onto its edge, carving up onto the watery wall. It's going to close out, I can tell—the wave's going to break all at once, instead of peeling in the way that makes for good surfing. So I shoot still farther up the face to launch myself over its lip, out the back. I'm airborne when I realize that the dolphin has likewise launched itself. We hang suspended together in the sky—water and land mammals, side by side in the realm of the birds.

From the apex of my own flight, I watch my fellow flier spear nose-first into the water, vanishing before my less-graceful splashdown.

Surfacing, I notice another surfer smiling at me, awestruck.

I say stupidly, "Did you see that? Did you see what just happened?" 

"Cosmic," he says. "Totally cosmic."