The cave is known as "Flatliner" and I immediately found out why: As the tide surged inward, a swell picked me up and nearly pinned me to the jagged ceiling. I flattened myself in my kayak and almost kissed the roof of the cave before dropping smoothly back down. Farther back in the bowels of darkness was a cobblestone beach where several harbor seals were relaxing on the damp rocks.

As well as harboring countless caves such as this one, Santa Cruz, the largest of the Channel Islands archipelago, is home to a unique blend of plants and animals. Close to the mainland yet worlds apart, the island takes you back to what California used to be. On a clear day you can even see the Santa Ynez mountains hovering over the coast. Endemic species like the island scrub jay and island fox live here and nowhere else. The caves themselves are a haven for sea lions, harbor seals, western gulls, and black oystercatchers, giving rise to the island's moniker as "the Galapagos Islands of the North."

For paddlers, however, its caves are the main attraction. More than 300 caves on the island are 150 feet or longer. Some are gaping holes with both entrance and exit visible from the water. Others, like "Marge" (named for the famous mother on "The Simpsons"), have narrow entrances difficult to slip into. Once I got on a straight line with Marge the image was clear: big hair, and the distinct facial outline. As I paddled past the entrance, another kayaker tried slithering through the extremely narrow gap, but the combination of swell and current slammed her into the wall, toppling her inside. I grabbed onto her kayak and backpaddled her out of the narrow opening. On a determined second attempt, she correctly anticipated the surging ocean and slipped through unscathed. A lesson was learned: although the caves offer tremendous exploration opportunities for sea kayakers, they can also be dangerous.

Next stop was Cavern Point, an enormous cave with a mouth reaching 40 feet to the ceiling. It has a steep rocky beach at the rear where territorial male sea lions let out bellowing barks at kayakers who paddle near their turf. Moving on, with a steady northwest wind and current at my back, I paddled to Scorpion Rock. The tide was peaking when I eased into the entrance where the sun's rays created a luminous interior, resembling the color of an indoor swimming pool. When I exited, a pair of black oystercatchers flew off in front of me, their orange beaks standing out on the rugged shore as they foraged for mussels, crabs and oysters.

Next came Painted Cave, one of the largest sea caves in the world. This sinister looking cavern rises to 250 feet, is over 1,200 feet long and rests on a fault and a lava tube. The cave has four separate chambers, with water reaching a depth of 25 feet. Making a couple right turns, then a couple of angles left, I eventually reached a cobblestone beach where my headlight made out the glowing eyes of several sea lions. Not wanting to stress them, I turned around and stroked for the beaming light of the exit.

By the end of the day, I had been in and out of countless, twisting passages. Yet it was only a fraction of the island's treasures. And as I waited for the boat to take me back to the mainland, I knew I would return - just like the Chumash Indians - to an island just 25 miles away from the coast, but worlds away in beauty.