Hawaii's exquisite "Garden Isle" of Kauai is just a short flight from burgeoning Honolulu. A paradise of stunning canyons, jungle-clad cliffs, and quaint, tranquil towns, Kauai invites any excuse to linger.

Unfortunately, I had to move fast. A 3 a.m. wake-up call had rattled me into consciousness; my boat was leaving at four. It was too early even for a mongoose to scamper across the road as I hastened south on rural Kaumualii Highway to the boat landing near Hanapepe, off Kauai's southwest coast. I pulled off onto a dirt drive and wound behind some light industrial buildings to water's edge. Some floodlights illuminated the scene, and I could now make out the vessel that was to transport me across eighteen-mile-wide Kaulakahi channel. Not an interisland charter serving cocktails, this tub looked like an amphibious landing craft mothballed after the Korean War.

Neither were the passengers the giddy honeymooners or retirees who "can't believe" they're in Hawaii. From the looks of them, these were salt-of-the-earth locals who, like me, had dragged along mats, tarpaulins, and inelegant bundles of personal effects, and were unceremoniously sprawling on the deck. Did I say it was 4 a.m.?

Our port of call was not one of the cushy resorts favored by the pampered classes but Niihau, known in Hawaiian as kapu, forbidden. Niihau, when it is mentioned in Hawaiian travel brochures, is usually touched on with intriguing brevity, summed up with an artful turn of phrase to the effect of, "Don't even think about it." The seventh- largest Hawaiian island, it is home to about two hundred people whose direct lineage antedates contact by British explorer Capt. James Cook, who discovered the islands in 1778.

Access to Niihau is strictly controlled by the island's owners, the Robinson family, whose Scottish ancestors purchased it in 1864 for ten thousand dollars in gold. The only island where Hawaiian is spoken as the first language, Niihau is a unique link with Hawaii's indigenous past and the object of fierce, if wildly divergent, opinion across the state. And the Robinsons are surrounded by almost as much mystery as the island itself. Are they exemplary stewards of Polynesian heritage who singlehandedly have preserved the only true vestige of old Hawaii? Or, as some activists claim, are they colonial occupiers who ought to recognize the sovereign right of Hawaiians to the lands of their ancestors?

For a modern cosmopolitan society that reveres its Polynesian heritage, the preservation of an entire island culture and ecosystem by a Calvinist haole (white) family is maddeningly contradictory. A "traditional" claim on the land itself raises questions. The island was among the largest parcels of land to come into private ownership in a mid-nineteenth-century upheaval known as the Great Mahele. This Western-style land reform deprived chiefs of often-capricious authority over land dispensations and empowered formerly landless Hawaiians for the first time with recognized property titles.

The Hawaiian monarchy, moreover, deemed the sale of Niihau, the westernmost island in the archipelago, a stroke of unusually good...