Automatic Information System (AIS) devices have been required on large commercial ships since 2002. Their popularity is growing in the U.S. recreational sailboat market, thanks to the Federal Communications Commission’s (FCC) recent approval of AIS Class B transponders. Some devices allow users to send and receive information about a ship—location, size, speed, call sign, and MMMI number. Others, like the Raymarine AIS 250, only receive AIS broadcasts from other AIS-equipped ships. The Raymarine AIS250 receives AIS Class A and AIS Class B broadcasts. Practical Sailor found that the device performed well, and was user-friendly and easy to install. But, for a receive-only unit, it’s pricey: $980, or about three times…