There is no difference between USD and Aqua-Lung
Must be an East Coast thing...I guess?
During the Depression and war era of the 1930's and 1940's, young skin divers prowled the coasts and lakes of America to hunt for fish, lobster, abalone, or any of any array of fresh seafood that was considered a luxury to these young divers. Equipment back then was either homemade or military surplus and consisted of little more than a mask or goggles. The lucky ones had long johns to fight off the cold and sometimes even a pair of surplus fins. Formal training was unnecessary and consisted of little more than practicing your breath hold technique.
In 1948, Rene Bussoz of Rene's Sporting Goods of Westwood, California, was convinced by Jacques-Yves Cousteau to import a new design for a self-contained underwater breathing unit, known as the Aqua-Lung, which would allow divers to stay under water for extended periods of time. Rene imported 10 of these units and, once these "bubble machines" were sold, everyone thought the market had been saturated. Within just a few years, however, Aqua-Lungs could be found in several shops across the country and a new breed a diver was entering the water that didn't need to have the great physical stamina required of breathe hold divers. The Aqua-Lung created a swell of new divers and Rene's Sporting Goods became U.S. Divers.
The Aqua-Lung was sold to anyone with enough money and came with training little more than a warning to "not hold your breath." The only formal training programs were found in the military, scientific institutions such as Scripps and Woods Hole, and in the dive clubs. In 1951 Jim Auxier and Chuck Blakeslee started a magazine called The Skin Diver (later renamed Skin Diver Magazine). They hired a man named Neal Hess to write a column called "The Instructors Corner" to cover teaching techniques for this blossoming sport. Hess soon began certifying divers to become instructors by reviewing their course outlines and then running their names in the column. This new program was called the "National Diving Patrol."
Check out this link on the history of diving:
http://www.divinghistory.com/articles.htm
USD has been around as long as diving itself no other company can make that statement!
