Today's MIT Technology Review reports an interesting demonstration of the ease of spoofing AIS data: http://www.technologyreview.com/news/520421/ship-tracking-hack-makes-tankers-vanish-from-view/ "One online service was fooled into showing a real tugboat disappearing from the Mississippi and reappearing on a Dallas lake, and depicting a fake vessel traveling off Italy on a course that spelled out the hacker term for a compromised system: 'pwned.' " Once you think about the origin of the data stream that feeds an AIS transceiver, it's easy to see how spurious information can be injected. Just another piece of evidence that we shouldn't assume everything on the LCD monitor is true. Cedric Walker The Office II Great Harbour N37