It’s 11 P.M., and I’ve just crawled from my bunk for my midnight to 6 A.M. watch. I arrive on deck to hear Sesario order everyone to drop the jib. He has made the decision to ride out a fierce storm with our sails down, what sailors call running under bare poles.

Balancing on a narrow plank in driving rain, two crew members struggle to gather the galloping jib as our boat rises and plummets down 15-foot waves. There are no winches and no roller to furl up the sail onto the headstay—only ropes, cleats, and brute strength. As a matter of pride, none of the crew wear life jackets. It looks as if the sail is going to get away and the two men will be flung out to sea, but somehow they wrestle it in and tie it off.

Tired, wet, and cold, they climb into their hammocks in the tomblike hulls of the Alingano Maisu, our 56-foot catamaran, a modern version of a traditional Hawaiian single-mast, double-hull sailing canoe. There is nothing left to do but rest and hope that our vessel holds up against the howling winds.

We’re in the Federated States of Micronesia, in the Caroline Islands, where people say that palu, local master navigators, have magic. They ply the waters of the Pacific in traditional hand-carved sailing canoes made of mahogany and breadfruit wood and talk to the clouds, currents, seabirds, waves, and, legend has it, ocean spirits, relying largely on the stars as their guide. The Maisu has no GPS unit to plot a course, no radar to help with navigational hazards, no fax machine with daily weather updates, and no satellite uplink for Internet access. I don’t know if our captain, Sesario Sewralur, a palu and the son of the great Mau Piailug, Micronesia’s most famous navigator, possesses magic or not, but if he does I want him to use it.

It’s our sixth night at sea, and malevolent black thunderheads have closed in around us from the north and the east. Earlier in the night, Tony Piailug, Sesario’s brother, did his best to tame the gather...