Author: Mark Harris

Explore Elast year, Bjorn Bergman noticed something strange about a fishing boat off the coast of Mauritania.Like other large ships in those waters, this trawler broadcasts Automatic Identification System (AIS) radio signals. AIS information contains a ship’s name, location, speed, and course—critical data to help nearby ships safely avoid each other. All large vessels are required by international law to use AIS for navigation, and the data is also useful for fisheries monitoring organizations. But this trawler’s AIS feed is unique. Instead of showing a consistent track as it slowly laid its nets, the ship seemed to leap impossible distances…