Distress Calls are made by lifting a small plastic cover (usually red) and pressing the switch that was covered for about three seconds. This action will switch all DSC radios in range to channel 16 and will broadcast your MMSI number and GPS coordinates. A distress alarm will be sounded on all radios in range and they may be given the option to save a waypoint so they can navigate to the distressed vessel. For all this to work, all DSC radios must be connected to an active GPS receiver. The range of the distress call is determined my several factors. These factors include the following for the radio placing the distress: power output (range of 25 to 1 watts), gain of the antenna (very low gain for rubber-ducky to 9+ dBi), height of the antenna. Similar factors exist for the receiving radio. You may be lucky and be in range of a coastal Coast Guard station increasing the range well over 25 miles.
If you accidently make a Distress Call, tune to channel 16 and make an all stations
announcement saying that the call was accidental and everyone should ignore the DSC Distress Call.