Nation: Mystery at 400 Fathoms

As the Yarmouth Castle pulled out of Miami, the towers of the beachfront hotels sparkled across the unruffled bay. Sailing with 375 passengers—more than 40 from a senior citizens' club in Pompano, Fla.—and a crew of 174, the cruise ship headed out on her twice-weekly, overnight run to Nassau. By midnight most of the passengers had gone to bed. At 1 a.m., 120 miles east of Miami, many were awakened by the smell of smoke seeping under their cabin doors. The Yarmouth Castle, a 5,000-ton, 38-year-old veteran under Panamanian registry, was on fire.

Two nearby ships, the Bahama Star and the Finnpulp,...