The soft key is a button that can call up several different functions depending on the operating status of the device that hosts it. On a device, the soft key is usually activated when the display shows an information box with the meaning of the function that the indicated soft key will activate.
In the nautical sector there are several devices that use it. They are normally located at the bottom of the screen, but they can also be located at the top or at the sides. They can be in rows of 3, 4 or more softkeys.
Where the touch screen cannot be used for safety reasons, the soft key is widely used, precisely because the method of use is similarly intuitive and at the same time retains the security pressure / action of a button.
In the nautical and naval sector we often find them in fixed VHF, navigation plotters, radars and many other professional devices.