About five years ago on a Portugal to Canary Island trip. The system gave so many false alarms we shut it down and the boat's owner had it removed in Las Palmas and returned as defective. Hopefully they have improved it, but at the time we considered it dangerous to use due to the false alarms. The unit would go off even when the crew devices were all on the chart table and at a rate of about one alarm an hour, then we had to manually clear each device to see who was "missing".