American naval team demonstrate new device for submarine life saving.
New London, Connecticut, United States of America.
Introductory intertitle reads: "Few tragedies are more terrible to contemplate than the fate of a disabled submarine's crew, at the bottom of the sea. Here is the latest American life-saving device at work."
Various shots of young naval officers demonstrating a device which enables them to breathe at the bottom of the sea. Naval students climb into a compression chamber to get used to air pressure. Various shots of the men "showing they can stand it". We then see the men in the actual submarine chamber. Water is let in until it is level with the safety hatch, the pressure of the air releases the hatch and the men swim out.
The Pathe cameraman is sent down to film underwater scenes. The commentator is quite excited that all the men come up from their underwater experience: "proving that the lung is a real life saver."