Bob Croft, Navy Diver, Submariner, Father of American Freediving

December 30, 2013 Updated: April 28, 2016

He is 80 years old. Born and brought up on the shores of Connecticut and Rhode Island Bob Croft has salt water in his blood. His earliest play was on the bays, waterfront and harbors of New England. As a little boy he was champ diving down for the delectable quahog clams in Narragansett Bay. What fun to swim, row his boat with pals and explore the marine estuaries near home.

Bob Croft remembers the great hurricane of 1938. He was about four when the violent storm wiped out much of New England’s waterfront and devastated homes and businesses. He was 7 when the Japanese attacked Pearl Harbor. He played war games with his friends from imagined bunkers the boys dug overlooking the bay.

When the Korean War broke out Bob’s patriotism saw him urge his parent’s to allow him to enlist in the U.S. Navy Reserves. They would not let him enlist in the regular Navy. His childhood friend, a year older, did enlist and was killed in combat. Bob requested active service. It was granted. After boot camp he was assigned the submarine service in Groton, near where he was born. From this point on Bob’s chronology of his life, in this remarkable autobiography, describes his submarine adventures.

Any insider’s view of early diesel-electric boats would be fraught with the perils of submarine service. The Navy still used World War II era submarines to patrol after the Korean War ended. The end of the war resulted in Bob’s being discharged from service after serving 21 months. His life seemed dull. He’d married his childhood sweetheart yet work in a gas station, jewelry store and starting his own bakery business paled by comparison to the adventurous life in underwater boats.

Bob’s wife Edna supported his decision to reenlist. He served in a succession of submarines until he had 12 years sea service. The Navy transferred Bob to the submarine base in Groton where he qualified as a Scuba diver. He became an instructor at the escape training tank built on the Thames River sub base in Groton.

Bob describes his trepidation at first as his instructor-trainer beckoned him to dive down into the 118-foot deep training tank. The colossal tube was required training for Navy submariners. It provided various escape methods over the years from simulated boats sunk in the deep. After a second chance, Bob swam down into one of the bubbles the instructors used. Little by little he increased his breath holding times from 90 seconds to a remarkable 6 minutes.

All of the Navy instructors were remarkable free divers. They supervised recruits during escape training to insure they exhaled on the way to the surface. In the company of accomplished Navy instructors, Bob excelled. A medical examination saw him recruited for the Naval Submarine Medical Research Laboratory, the actual patron division that had charge of the escape training facility.

The medical examination startled scientists. Bob Croft’s lung volume was half again greater than the average adult male, “…and my vital capacity was almost double average,” he writes.

Here was a specimen they could experiment on. In those days the theory was that any breath-hold dive to depths greater than 120-feet would cause the lungs to shrink to the size of oranges and thus collapse the thorax.

Bob developed a trick since childhood swinging in his hammock back in Rhode Island. He packed air into his lungs using his tongue. Awkward as it sounds it worked for him. He just kept pushing air back into his lungs with his tongue. He called the technique ‘zero float.’

Doctors and researchers tested Bob over and over and concluded that he could safely dive to 200 feet without suffering thoracic squeeze. This would prove to be an American record breath holding dive. Of course French and European spearfishermen had been diving deep long before the U.S. Navy’s experiments.

Jacques Mayol and Enzo Maiorca established record dives as did many early pioneers in the sport. All of this went against the concept of thoracic squeeze. The U.S. Navy wanted to find out and understand the science and physiology of deep breath holding. Bob Croft became their experiment.

Bob’s book relates many inside details about the rivalry between Jacques Mayol and himself. One incident he relates is about Mayol passing out while using Scuba at 250 feet to witness Bob’s deep free diving descent wherein Croft beat Mayol’s record.

‘Bob Croft Navy Diver, Submariner, Father of American Freediving’ is an easy read. The pages seem to fly by in his relaxed, first person narratives of events during his 23-year career in the U.S. Navy. Bob and his wife Edna now live in their 23rd house in Palmer Township, PA where he says, “Perhaps the anchor has finally been dropped. Time will tell.”

The book is illustrated with black and white and color photographs, graphs and charts. It is soft-cover 9″ x 6 1/4″ published by the Italian medical book publishing house of Idelson-Gnocchi. It is available in the U.S. for $30 from their U.S. office at 1316 King’s Bay Drive, Crystal River, FL 34429 via telephone at 352 361 9585 or fax 561 207 7132. You can visit Bob’s website at The book’s ISBN number is 1-928649-45-9.