FWIW ships do this. Many of you might know, but for some of you this might be your lucky day to learn about AIS : ) All passenger ships and most other commerc

FWIW ships do this. Many of you might know, but for some of you this might be your lucky day to learn about AIS : ) All passenger ships and most other commercial ships are required to have working AIS transmitters (the only exception I know of are fishing vessels while fishing - as to not be forced to shout out their exact location). AIS is picked up by other vessels, coast guard installations, military, a number of receivers in peoples homes and also on satellite (one example I'm familiar with: http://www.kystverket.no/en/EN_Maritime-Services/Reporting-and-Information-Services/Automatic-Identification-System-AIS/Satellite-based-AIS/ http://www.kystverket.no/en/EN_Maritime-Services/Reporting-a...) On https://www.marinetraffic.com/ https://www.marinetraffic.com/ you can watch ship traffic live, and they even have a program where they might give away free receivers. Source: I used to work with large scale radio and radar systems.