Many of the on-board electronic instruments have this function at their disposal, which can sometimes be inserted by means of a dedicated button.
For example, in nautical GPS, two buttons are often inserted: "zoom in" and "zoom out". The "zoom in" zooms in to an area that becomes the narrowest area, but with more possibilities to show more specific details. While zooming out cancels the zoom in operation, showing a larger area, but with less chance of distinguishing details.
In fishfinders it is used to obtain more details on a specific depth level, many use it to better monitor the configuration of the bottom, or an intermediate depth band where it is suspected to find fish.
In nautical binoculars or marine cameras, the zoom function is optical and allows a greater magnification of the area concerned, but this decreases the field of view (FoV).