This app is a very specialist and will be of limited use to the general public. It is designed to allow an Android phone with a built in GPS to transmit your position to a GMDSS enabled marine VHF with an NMEA 0183 interface using a Bluetooth adapter module. Limited data can be sent to an autopilot, or other equipment with an NMEA 0183 input.
It is necessary to build some electronics. Also, the re-flashing of the Bluetooth module requires some computing knowledge. Instructions on my prototype can be found at
A photo of my prototype Bluetooth to NMEA 0183 module is shown in the feature graphic. There are many ways to achieve the same thing. Or true converters can be purchased at some cost (the components for the prototype circuit cost about £10). It is possible that at some point in the future I may be able to supply modules pre-assembled and pre-flashed to the data rate of 4800 baud, which is what NMEA 0183 requires.
At present, NMEA 2000 is not supported.