Many of the sanctuaries are reached by boat (plenty of commercial outfitters offer trips), but some nestle right up against the mainland.

The waters immediately surrounding most of the 1,700 islands that comprise the Florida Keys have been designated as a national­ marine sanctuary since 1990. Step off most beaches, throttle a boat, or push a kayak from almost any boat ramp, and you are smack-dab in the sanctuary, making the Florida Keys National Marine Sanctuary (floridakeys.noaa.gov, 305-743-2437) one of the most convenient sanctuaries in which to play. An added convenience is that, everywhere you turn, there are outfitters who offer every means of watery pleasure - world-class fishing, reef and wreck diving, kayaking, mangrove and glass-bottom-boat tours, or simply drifting beneath a blood-red sunset, mai tai in hand. It's as if Disneyland has plunked its concessions in the heart of Yosemite.

Wilderness purists might look down on this commercial conflagration, but it doesn't bother me, because in the Keys, there is still plenty of water to escape to. Such is the magic of wilderness.

On Summerland Key, I push my kayak into the water and paddle west into Florida Bay. Cumulus clouds erupt into the sky like cotton candy towers. Beneath the kayak, sand and sea grass slide languidly past.

I paddle until I find what I am looking for. Tying the kayak to a branch that juts from the mangrove hammock, I pull on fins, mask, and a snorkel, and slide in.

The world turns sooty gold. The tepid water is only about three feet deep, but I'm not seeking blue whales or kelp. Mangroves serve as juvenile nurseries for many fish, protected romper rooms before the fish move into the ocean and the food chain operates at a merciless speed.

They morph from the gold, the treasure I seek - a dozen juvenile barracudas hovering motionless, beautiful and bewitching; same needle physique, same outsize jaw, perfect replicas of adult barracudas, yet no bigger than my thumb.

I have been here before, perhaps even seen the forebears of these pugnacious youths, but it doesn't matter. I'm alone in nature's cathedral, privy yet again to a special moment and place, and the goose bumps rise.