Not since the 17th and 18th centuries, when cutlass-wielding outlaws terrorized the Caribbean, has piracy been so rampant on the world's oceans. Acts of piracy soared worldwide in the first six months of this year, reaching an all-time high of 234 attacks and claiming the lives of 16 sailors, according to a report released yesterday by the London-based International Maritime Bureau. The new figures, which amount to a 37% increase over the same period last year, represent the worst six-month period for piracy since the bureau, a specialized division of the International Chamber of Commerce, started compiling statistics in 1991....