Abstract: A carbon dioxide absorber (1) and a closed-circuit breathing apparatus (2) with the carbon dioxide absorber are based on the carbon dioxide absorber having an inlet (3) and an outlet (4) gas-tight connectable by a flow duct (5), in which a material (6) is arranged, which absorbs some carbon dioxide contained in the breathing gas stream sent through the material. The flow duct (5) is enclosed in some areas by a housing (7), in which a window element (8) is arranged. A display element (9) arranged movably in the flow duct (5) is visible through the window element from outside of the housing and/or through which window element the radiation reflected by the display element (9) exits to the outside. A distance between the window element (8) and the display element (9) varies as a function of the quantity of carbon dioxide-absorbing material arranged in the flow duct (5).

Abstract: A diving apparatus (10) supplies breathing air (L) and includes a basic body (12), a tank interface (20), a pressure reducer (22), a mouthpiece interface (24), and a display device (30). The tank interface connects to a breathing air tank (90) for the inlet of breathing air into the diving apparatus. The mouthpiece interface is configured for connection of a mouthpiece (92) for the supply of breathing air from the diving apparatus. The pressure reducer is arranged in a gas path of the diving apparatus between the tank interface and the mouthpiece interface for reducing gas pressure. The display device includes a display instrument (32) and a display line (34). A holding element (40) is configured to detachable fasten the display line at the basic body. A diving system (100) is provided including the diving apparatus (10), a breathing air tank (90) and/or with a mouthpiece (92).

Abstract: The mast device for a submarine comprises a guiding means, a vertically traversable mast guided therein and information means which are provided at the mast upper end and which are in electrical interaction with the inside of the submarine for emitting and receiving information. The information means are arranged in a buoyant unit held on the mast upper end without connection to this. The buoyant unit is fastened to a flexible coupling means which may be let out and retracted and which is of the length essentially of the maximum desired observation depth of the submarine.

Abstract: The mast device for a submarine comprises a guiding means, a vertically traversable mast guided therein and information means which are provided at the mast upper end and which are in electrical interaction with the inside of the submarine for emitting and receiving information. The information means are arranged in a buoyant unit held on the mast upper end without connection to this. The buoyant unit is fastened to a flexible coupling means which may be let out and retracted and which is of the length essentially of the maximum desired observation depth of the submarine.