An Aqua Lung® is a trademarked device to allow breathing under water. Originally invented by a pair of undersea explorers in the 1930s, the Aqua Lung® uses open-circuit technology to give the user fresh air and expel used air. Aqua Lungs® are considered outdated technology by some critics, but remain a staple product in the military as well as the general scuba community.
Jacques-Yves Cousteau and his partner Emile Gagnan are often credited with inventing the device that would become known as an Aqua Lung®. Cousteau, a famous underwater researcher, took inspiration from the 19th century inventors of the diving helmet to create his underwater breathing apparatus. Gagnan, far less famous, nonetheless developed the regulating mechanism that controlled air supply from the pressurized tanks. Cousteau used their combined invention to film long sequences in deep water, something that had not been possible using only snorkeling technology. The success of Cousteau's films, including Palm d'Or winning documentary The Silent World, greatly helped popularize marine biology and are considered major contributing factors in the rise of marine conservation efforts.
After the patent for the original invention expired in the 1960s, Cousteau's device was purchased and trademarked by a diving-supply company then called U.S. Divers. Although the term was in use as a generic word for scuba equipment, the new trademark laws quickly ensured that any casual use was to be discouraged. U.S. Divers changed its name to Aqua Lung America after its most famous product, and continues to be a major supplier of dive equipment.
The United States military has been availing itself of Aqua Lung® technology for nearly 50 years for underwater training and missions. Research and development of scuba products for military use has been a primary focus of the Aqua Lung America company. In addition to life-support materials, the company provides specialized equipment for Navy and special force units, including scuba products for dangerous missions such as Explosive Ordinance Disposal (EOD.)
Aqua Lungs® use a type of technology called open-circuit in order to help divers receive clean air and expel used air. According to critics, this type of scuba equipment can be troublesome, as it leaves behind a distinct trail of bubbles as air is exhaled which may frighten or anger nearby animals. Closed-circuit equipment recycles air by passing exhaled air through a chamber that removes carbon dioxide and returns it to breathable oxygen. Not only do closed-circuit diving tanks reduce the bubble trail, they also give the diver more time underwater by use of the recycling process.