You would have thought my son had found a hundred-dollar bill at the local beach rather than a clamshell. To hear him tell it, though, a few centuries ago that's exactly what this shell might have been.

Thing 2 produced the shell from his overstuffed Spider-Man backpack and began a brief history on how people along the Long Island Sound once used shells as currency. "But only if it has this blue part," he said, pointing out the patch of color on each half of the shell's inner lip. "If it wasn't blue, it wasn't money."

Though most of my four decades have been lived within a few miles of the Connecticut shores, my son -- at age 7 -- is now our household authority on the city's beachfront and aquatic life. That's just what I was hoping he'd become when he first told me he wanted to go to the summer camp run by a local nonprofit group that educates people about the wonders of the Long Island Sound and our obligation to protect it for future generations.

Growing up as I did in the one-acre-zoned isolation of upper suburbia made it easy to forget that our city fronts not just water but a vital Atlantic estuary that has provided food, livelihood and recreation to billions throughout time. But that is life in that part of town. It is sometimes like being stranded on an island where the only escape route of merit is a high-speed ribbon of asphalt running parallel with but never to the shore.

Besides, I come from a family of strict non-adventurers. Any trip from our neighborhood valley to a point much farther south than the all-you-could-eat salad bar at the old Brock's was believed to require a three-day supply of drinking water and a Sherpa.

This, however, should not be my son's life. He has the instinctive curiosity about nature and geography that I lacked as a child and then some, and I envy him in that way. After taking part in a free program SoundWaters offered this past winter at his school, he was eager to spend a few weeks of his summer learning more about how to tell a male diamondback terrapin from a female (all in the tail, people, all in the tail) and chasing spider crabs along the shores.

True to form, in recent days he has filled us with facts about how flounders evolved and what life is like in a salt marsh. Extracting each of these tidbits, though, required the usual parental pulling and prodding and, frankly, that left me a little disappointed. With his brain being crammed with new knowledge, I had expected regular deluges of tidbits without me needing to use that special singsong tone I normally save for coaxing out answers about his school day or why he hit his big sister.

Then one night, as I stepped onto the deck to cover the Weber following an evening's grilling, a full moon surprised me with its pale orange glow radiating mystically through the August haze. I called into the house for the kids to rip themselves from their portable gaming systems. All I hoped to hear from at least one of them was a simple "cool."

Thing 2 looked up and suddenly broke from his Nintendo trance.

"The horseshoe crabs are laying their eggs!" he said. "They only do that during full moons. They're laying them right now down on Cove beach."

That's when I knew camp had been worth every clam I had shelled out.