By T. Rees Shapiro
Washington Post Staff Writer
Friday, February 18, 2011; 10:54 PM
Christian J. Lambertsen, who as a medical student in 1939 invented a revolutionary underwater breathing system used by the military in World War II and who later helped coin the popular acronym to describe his device and others like it - scuba - died of renal failure Feb. 11 at his home in Newtown Square, Pa. He was 93.
Dr. Lambertsen, who had a second home on Maryland's Eastern Shore, was a longtime professor at his alma mater, the University of Pennsylvania School of Medicine. He was an expert on respiratory physiology and diving-related ailments.
His 1939 invention, the Lambertsen Amphibious Respirator Unit, or LARU, is considered a forerunner of the scuba technology used today.
In 1952, Dr. Lambertsen and a colleague wrote a paper for the National Academy of Sciences describing his "Self Contained Underwater Breathing Apparatus," which they shortened to scuba.
Before World War II, military divers wore clunky metal helmets that pumped breathable air through hoses tethered to boats on the water's surface.
Dr. Lambertsen's LARU let divers swim freely and stealthily. It used pure oxygen and was a closed system. Equipped with a carbon dioxide filter, it enabled the diver to re-breathe the air he exhaled while underwater, which made the system bubbleless.
After the Navy rejected his device at first, Dr. Lambertsen demonstrated the LARU in the swimming pool of the Shoreham Hotel in Washington in 1942 to the Office of Strategic Services, the World War II predecessor of the CIA.
Not only was the OSS impressed with the invention, the nascent spy agency saw great potential in the young medical student, who was also an experienced diver.
After he graduated from medical school in 1943, Dr. Lambertsen joined the Army Medical Corps and was recruited to the OSS.
He helped train members of a newly formed OSS maritime unit in the use of his underwater breathing system in the pool at the U.S. Naval Academy in Annapolis.
One of the men Dr. Lambertsen trained was able to swim more than a mile underwater in the Potomac River and remain submerged for 48 minutes.
Dr. Lambertsen's device was further tested in Operation Cincinnati, in which OSS swimmers clandestinely infiltrated the heavy defenses of the U.S. Navy harbor at Guantanamo Bay, Cuba, and blew up an old barge.
The mission was a resounding success, a top-secret government report later concluded, because "Navy sound detection gear did not reveal the presence of underwater swimmers."
Dr. Lambertsen was deployed during World War II to Burma, where he worked with OSS units on underwater infiltration and espionage missions. Maj. Gen. William J. Donovan, the leader of the OSS, awarded him the Legion of Merit.
After the OSS was disbanded in 1945, Dr. Lambertsen arranged to demonstrate LARUs to the different military branches.
In 1948, he began training the Navy's elite underwater demolition teams, the precursor of the Navy SEALs, to use the system.
During one training exercise near St. Thomas in the U.S. Virgin Islands, Dr. Lambertsen and another swimmer made the first exit and re-entry from a submarine.
In the 1950s and 1960s, collaborating with the J.H. Emerson Co., Dr. Lambertsen developed an advanced version of his underwater breathing system. It was used by Navy special operations units until the 1980s.
In 2009, Dr. Lambertsen received the distinguished service award from the OSS Society, which honors the old intelligence service.
Presenting the award, Adm. Eric Olson, commander of the U.S. Special Operations Command, said Dr. Lambertsen and his LARU enabled the OSS to conduct "previously impossible missions."
Christian James Lambertsen was born May 15, 1917, in Westfield, N.J. He graduated in 1938 from New Jersey's Rutgers University.
He conducted his first experiments on underwater breathing systems during vacations to the Jersey shore, using contraptions rigged with hoses and a bicycle pump.
His prototypes evolved during medical school, and he made a major breakthrough by adding carbon dioxide filters from anesthesia equipment.
In 1943, Jacques Cousteau and another French diver invented an improved scuba system called the "Aqua-Lung," which let swimmers dive deeper and stay underwater longer.
Dr. Lambertsen joined the medical faculty at the University of Pennsylvania in 1946 and became a professor of pharmacology in 1952.
His wife, Naomi Hill Lambertsen, died in 1985.
Survivors include four sons, Christian J. Lambertsen Jr. of Chapel Hill, N.C., David Lambertsen and Richard Lambertsen, both of Easton, Md., and Bradley Lambertsen of Wallingford, Pa.; and six grandchildren.
In his later years, Dr. Lambertsen enjoyed spending time at his waterfront home in Bozman, Md., where he raised cattle, kept honeybees and grew tomatoes, apples and pears.