Last year, Simrad introduced a new alternative to high-accuracy, fast-reacting compasses, its new HS50 GPS Compass. Using phase-change technology rather than positioning information from satellites, the HS50 reportedly offers accuracy to .01 degrees as it maintains true north. Even while the boat is motionless, the phase-change technology, along with two separate GPS antennae in an elongated housing, allow the unit to determine which way the boat is pointed. The rate of response is so fast that it can track a 90-degree turn in 1 second--much faster than you'd ever change course in a sailboat. Output is in RS-232, NMEA 183, and other digital protocols to allow connection with virtually any other equipment you might have in your nav station, including autopilots, radar, and computers. Aside from its electrical-power requirement and its relatively large size, perhaps the only disadvantage of the HS50 is its price. At slightly under $8,000, accuracy must be highly prized.