A system including binoculars augmented with a computer-generated virtual display of navigation information (hereinafter referred to as "nav glasses") and marine navigation systems employing such binoculars. The computer-generated display is superimposed on the real world image available to the user. Nav glasses also have the components needed to link them to a navigation system computer which is utilized to generate the see-through display of the navigation information. They are preferably equipped with sensors compass and an inclinometer for acquiring azimuth and inclination information needed by the navigation computer and a sensor for measuring any magnification of the field of view. The nav glasses can be employed to lock onto a moving target, which can then be tracked by onboard radar. The navigation system in which the nav glasses are incorporated also accept inputs from other sources such as a shipboard compass, a GPS, and other navigation aids; and a route planning system. The field of view of the nav glasses is calculated from information obtained from the nav glasses and navigation sensors, and a display manager generates a pre-fetch display of navigation information from the route planning and radar inputs. This pre-fetch display or image extends well beyond the nav glass field of view. Consequently, as the glasses are shifted from side-to-side or up or down, all that may be required to match the virtual display to the real world image is to align a different segment of the pre-fetch image with the actual field of view. Once the alignment of the virtual display of navigation information and the actual field of view is completed, the virtual overlay is transmitted in coded form to a video output component of the navigation computer and forwarded to the nav glasses where the virtual display is constructed and superimposed on the real world view.