There are times when you may prefer not to transmit your vessel's location over AIS, yet you may wish to continue to monitor the vessels around you. Cortex offers this option which is commonly known as Silent Mode. This Silent Mode has been coined "Stealth Mode" as it is a popular feature on Ocean Racing boats, where they may wish to be invisible to their competitors, yet still see shipping movements and continue to use collision alerts for safety.
There may be times, beside during a competitive ocean race that the stealth mode may be preferred. This may include fishing at your favorite and secret fishing hole, while at the dock or at the anchor, or if you are travelling in an area with a security risk and do not wish to be detected.
Cortex Stealth mode also inhibits your DSC system from sending position reports when requested by another DSC system, commonly known as buddy track. Cortex Stealth mode control can also be wired in to the GPIO port, and controlled with a switch.
To use the Stealth mode on your Cortex handset or on the Cortex Onboard app, tap the Transponder icon
Tick the Stealth mode switch -it is green when it is active and TX in not transmitting.
This is confirmed in the status report view Stealth mode off is also orange, on that same view.