The Gulf was trying to make its way through the shipping lanes around Japan’s southern archipelago, the gateway between the Philippine Sea and the East China Sea. Almost every day, hundreds of cargo ships coming to or from China, Japan, South Korea or Taiwan pass through these lanes. By Aug. 31 virtually every other vessel in the region had rerouted around the storm or was doing so. The Gulf was alone in a swath of ocean that stretched hundreds of nautical miles.