At Periscope Depth

The development history of submarine periscopes from the first beginnings in the 19th century on. Within the last 120 years, an impressive technological transformation took place in which the conventional glass-optic periscope with direct view at first became an opto-electronoic (optronic) periscope equipped with TV and infrared cameras and then was completely transformed to an optronics mast that does not penetrated the hull of the submarine any more.