“Diving by day” is the submariner’s term for operating submerged during the hours of good visibility.  In the control room of an American “boat” cruising in European waters, the diving officer directs the handling of the labyrinthine machinery which surrounds him port and starboard.  At the lower periscope, an officer makes a sweep of the horizon while in the background are the bow and stern planesman.

This is the submariner’s term for operating submerged during the hours of good visibility.  In the control room of an American “boat” cruising in European waters, the diving officer directs the handling of labyrinthine machinery which surrounds him port and starboard.  At the lower periscope an officer makes a sweep of the horizon, while in the background are the bow and stern planesmen.