All flights were made on moonlit nights so that visual navigation could be made by using rivers, lakes, railroad tracks, and towns as check points.

Where the chart indicates "Entry by visual navigation only", it must be assumed that the bottom contour is not 'given'.

It is the highest point on the conning tower, to provide for better visual navigation when on the surface.

A K-series bombsight provided integrated radar and visual navigation, with the optical portion extending through the nose of the aircraft in a small dome.

A further benefit is the support for visual navigation through the software system.

Two of the surviving crew managed to back the ship away from the station and dive, defeated, back into the wormhole, using visual navigation alone.

The guide is designed for use with compass, GPS, or visual navigation.

All visual navigation was being done by periscope.

You'll come out close enough for visual navigation on inert flight.

It also includes sufficient ground detail - towns, roads, wooded areas - to aid visual navigation.