Dr. Christian J. Lambertsen

Aquatic Pioneer

Dr. Christian Lambertsen
Dr. Christian Lambertsen
Maj Christian J. Lambertsen
Maj Christian J. Lambertsen with Special Forces Tab and Combat Diver Badge, 1996.
Dr. Christian Lambertsen
Dr. Christian Lambertsen

Dr. Christian J. Lambertsen was a pioneer in underwater operations. While a student at the University of Pennsylvania, he developed a closed-circuit underwater rebreather. A true innovation, it allowed the swimmer to remain underwater for longer periods and prevented detectable bubbles from escaping to the surface.

In 1942, Lambertsen demonstrated the system to representatives of the wartime Office of Strategic Services (OSS), who recognized its combat potential. After graduating in early 1944, Lambertsen was commissioned in the U.S. Army Medical Corps. Once in uniform, he was assigned to the OSS Maritime Unit, where he instructed swimmers in the use of his system, dubbed the Lambertsen Rebreathing Unit (LARU).

Maj Christian J. Lambertsen
Maj Christian J. Lambertsen with Special Forces Tab and Combat Diver Badge, 1996.

After the war, he coined the term Self-Contained Underwater Breathing Apparatus (SCUBA), and worked with the U.S. Army, Navy, Coast Guard, and non-military agencies such as the National Oceanic and Atmospheric Administration (NOAA) and the National Aeronautics and Space Administration (NASA). His innovations have helped shape U.S. Army underwater operations to this day.

Dr. Lambertsen was a staunch preserver of the history of the OSS MU. This page features materials graciously donated by his family to help foster an understanding of the legacy of Dr. Lambertsen.

Maj Christian J. Lambertsen interview

DESIGN

Christian J. Lambertsen is considered the “father” of combat underwater swimmers. He designed a prototype rebreather before the U.S. entered World War II. A student of respiratory physiology at the University of Pennsylvania, he became interested in the effects of gasses on the human body. Experiments brought him to the realization that that if carbon dioxide could be scrubbed from a contained circulatory gas system, a person could remain underwater for a much longer time.

Initially, he worked with the Ohio Chemical Company to develop an underwater rebreather, publishing a paper in 1941 in The Journal of the American Medical Association on the system’s use for saving lives. That same year, he demonstrated this system, later named the Lambertsen Amphibious Respiratory Unit (LARU), to the U.S. Navy Experimental Diving Unit. Although impressed, the Navy did not see utility in salvage operations.

In 1942, Lambertsen demonstrated an improved version of the LARU to the Office of Strategic Services (OSS) and British Special Operations Executive (SOE), both of which understood the application of the system to underwater warfare. The OSS unofficially employed Lambertsen while he was a student and worked with him to refine the system.

Side View LARU Model 10. Developed throughout 1943 and 1944. Patented 31 January 1945.
Diving Apparatus for Life Saving Work (back view) developed in 1939. Filed for Patent 16 December 1940.
Diving Apparatus for Life Saving Work (front view) developed in 1939. Filed for Patent 16 December 1940.
Lambertsen Diving Outfit (front view). Developed in 1940 and 1941. Patented 21 January 1942.
Side View Lambertsen Diving Outfit. Developed in 1940 and 1941. Patented 21 January 1942.
Rear View Lambertsen Diving Outfit. Developed in 1940 and 1941. Patented 21 January 1942.
OSS Developed LARU Model 10. Developed throughout 1943 and 1944. Patented 31 January 1945.
OSS Developed LARU Mark II. Silver Springs, Fl. Sept., 1943.
Diver displaying mouth piece of LARU Mark II
Lt. Fred Wadley wearing LARU Model 10 (LARU) (out of water)- late 1944.
Lt. Fred Wadley wearing LARU Model 10 (LARU) (out of water) - late 1944.
LARU Mark III, left side. Late Spring 1944.
LARU Mark II, behind.
Front View. LARU Model 10.
Side view, LARU Model 10.
Using the Lambertson Unit

TESTING

Upon graduating with a Doctorate of Medicine in 1943, Lambertsen commissioned into the U.S. Army Medical Corps, and was detailed to the OSS Maritime Unit (MU). Lambertsen continued to develop the LARU, coming up with several variations during the war. In addition, he personally trained two MU swimming groups on the use of the LARU, while at the same time writing and refining the program of instruction.

He also developed additional underwater equipment, including a device that allowed swimmers to communicate with each other at ranges of up to a hundred yards, a compass, and a neutral buoyancy container to help swimmers tow demolitions. This equipment, as well as pushing boundaries for the employment of the LARU through aggressive training, opened new possibilities for the employment of combat divers.

In late 1944, Captain Lambertsen deployed to Burma with a MU swimming group that conducted amphibious reconnaissance missions for the British XV Indian Corps as it secured the Arakan Coast prior to liberating Rangoon from the Japanese. Although they found that the LARU was not suitable in the murky waters of coastal Burma, the MU successfully worked in conjunction with an OSS Operational Group to help secure the coast.

Swimmer John Booth, USCG, Lt. Jg. Pool 1947. Photo for USN Diving Manual
Lt. John Booth wearing LARU, showing Lambertsen technique.
Sleeping Beauty and its pilot making the first successful rendezvous and docking with a submerged and underway submarine.
Sleeping Beauty approaching landing on USS Quillback, 1948
Diver exits Sleeping Beauty at bottom.
Lambertsen-designed neutral-boyancy container.
GM2C Norm Wicker, USN, and GM2C John Spence, USN on prototype of the silent electric surfboard wearing LARU MK II.
Two Sleeping Beauties on the cradles, Feb/March 1945, Galle, Ceylon.
Back View of rebreather.
Lambertsen limbing up onto dock after a test of an early rebreather.
Lt. Chris Lambertsen, U.S. Army, MC, Lt. Fred Wadley, U.S. Army, Maj Al Lichtman, USMC, and Lt. Dennis Roberts, Chief, Maritime Unit.
Operational Swimmer from Group II wearing LARU Model 10 climbing over Torpedo Net Defenses in Guantanamo Bay Cuba, Sept. 1944.
Underwater Operations

DEPLOYMENT

After the war, Major Lambertsen remained in the Army Reserves. He served on national-level underwater warfare boards and continued to train the Coast Guard, Navy, and Army in the use of the LARU and helped them develop underwater search and rescue and warfare techniques.

Additionally, he was the founder and director of the University of Pennsylvania Institute for Environmental Medicine where he continued to develop equipment that would assist underwater warfare.

His research into the effects of gasses on the human body pushed human limits in both deep water and space. Dr. Lambertsen is the namesake for the United States Special Operations Command’s Dr. Christian J. Lambertsen Award for Operational Innovation. In 2022, he was posthumously awarded the Special Forces tab for his OSS service.

Tweedy at bottom of anti-submarine net.
On board USS Burrfish before Gagil Tomil Island Mission, 18 August 1944. Recon Team during pre-mission dinner.
On board USS Burrfish before Gagil Tomil Island Mission, 18 August 1944. Recon Team during pre-mission equipment check.
Underwater Demolition Team logo.
Underwater Demolition Team beach landing.
Diver with mine.
S-48, 'ghost fleet' used to test underwater techniques post-WWII.
Landing ships offload at Ramree Island, 1945.
OSS Detachment 404 AFU 06 on inspection.
MU craft P-101 at high speed.
Lord Louis Montbatten Cmdr-in-chief, South East Asia Command, Arrives for Inspection of Detachment 404, Teknoff, India.
Lord Louis Montbatten visiting Arakan Field Unit of Detachment 404 Office of Strategic Services. Teknoff, India. December 1944.
Two Maritime Unit personnel in kayaks participating in Operation BOSTON.
Officer Group.
OSS OG/MU team receiving a briefing for a mission off the Arakan Coast of Burma.
SGTs Johnson and McCarron of the Aerial Delivery Equipment Division, US Army Natick Laboratories, checks the oxygen and harness of the HALO (High Altitude Low Opening) parachute assembly.
Sleeping Beauty through torpedo net.
Close up of cutting anti-submarine net.
Nassau Training Report