monitor escape trainees as they ascended in simulated escapes, to make sure they exhaled on the way up.

Prior to the Navy Bob had taught himself "lung packing" or "air packing," a technique of overfilling his lungs by the use of his tongue, cheek, and throat muscles. This technique allowed him to hold his breath for 5 or 6 minutes. While a tank instructor, in 1962 he was invited to the Naval Submarine Medical Research Lab, where as an always-eager volunteer he

performed as a subject and collaborative investigator for numerous submarine-related research projects, including evaluation of the Steinke Hood, testing some prototype diving contact lenses, subjecting himself to high frequency sonar at close range, blood shift during breath-hold diving, and numerous lung and body function tests involving high and low oxygen and CO2. He set and later reestablished several records for deep free diving. One of the breath-hold projects resulted in his being pictured on the cover of Science

Bob Ellsworth with Robert Croft

magazine. Some of the tests left him with a partial hearing loss and loss of visual acuity.

His lung packing technique allowed him to change his lung function tests from essentially normal values for a person his size to values half again as

large. This astonished the experienced researchers at NSMRL, but for some unknown reason they did not publish this finding. The method did, however, find its way into training for Navy SEALs, and through a retired SEAL it was later rediscovered in 1992 at an experiment in an undersea lab in Key Largo. From there the technique was studied at Duke University and later was exhaustively studied at several laboratories in Sweden. After NSMRL Bob was assigned to the 4-man lockout spy submarine X-1 that had been converted to a research vehicle. The crew all had to be experienced divers as well as

submariners. Results of studies with X-1 were mostly classified.

After the Navy Bob went to work for Tarrytown Labs, a descendent of the Union Carbide-Ocean Systems deep diving research lab, where he worked on, among other things, development of decompression tables for dives to 1000 fsw. He later worked for Ingersoll-Rand and then Dresser-Rand, where he did training and training videos. He is still being invited to participate in free diving competitions!

	Robert Croft Promotion shot before his first world record attempt. In the background is the Submarine Escape Training tower at Groton, CT.
	Robert Croft on the U.S. Navy experimental X-1 submarine on which he served.
	Robert Croft, Edna Croft (Bob's wife) and Ernie Colburn, his dive master.