Retired Navy Capt. Walter Mazzone, a decorated submarine officer in World War II and later a key figure in the development of deep-sea diving and submarine rescue procedures during the Cold War, has died at age 96.
Mazzone died Aug. 7 at his home in San Diego after congestive heart failure, according to his son, Robert, also a retired Navy captain.
As a submariner, Mazzone was involved in two of the war's most harrowing undersea missions.
He endured more than 30 hours of depth-charging by Japanese destroyers in the Makassar Strait off Borneo in 1943 after his ship, the Puffer, attacked a Japanese merchant ship. It was considered the longest such assault in submarine history.
In 1944, Mazzone was torpedo and gunnery officer aboard the submarine Crevalle when it was ordered to retrieve secret documents from a Japanese-held island in the Philippines.
Along with the documents, the sub was charged with rescuing more than 40 women, children and missionaries who had been hiding from the Japanese. One of the women was pregnant.
Mazzone is credited with bringing a goat aboard the submarine to provide milk for the children, including the newborn.
On the way back to Australia, the Crevalle was assigned to torpedo a Japanese convoy. A Japanese depth-charge attack damaged the Crevalle but Mazzone's expertise kept the submarine under control and allowed it to escape.
The incident — not including the goat — was later made into an episode of the 1957 television show "The Silent Service," which dramatized submarine missions of World War II.
Mazzone, then a commander, was interviewed at the end of the episode. "I don't think anybody who was aboard the Crevalle will ever forget our floating nursery," he said.
For his war service, Mazzone was awarded a Silver Star, Bronze Star with Combat V, and a Navy Commendation Medal with Combat V. He went on seven combat patrols.
Walter Francis Mazzone was born Jan. 19, 1918, in San Jose. He attended San Jose State, where he was a boxer and football player and graduated in June 1941. He had planned to become a doctor but instead joined the Navy in the early days of the war.
After the war he remained in the Navy Reserves and received a doctor of pharmacy degree from USC before going to work in his uncle's pharmacy in San Jose. In 1950, he was recalled to active duty and sent to Japan.
Later he was assigned to the Naval Medical Research Laboratory and joined the effort to enhance the Navy's deep-sea diving capability. With the Cold War underway, U.S. officials believed that maintaining superiority in diving and submarine capability was key to thwarting the Soviet Union at sea.
He became project manager for the Sealab program that sought to test how humans could adapt to long periods on the seafloor. Tests were done at sea-bottom locations off Bermuda, La Jolla and San Clemente Island, Calif.
Among other innovations, Mazzone and Lt. Harris Steinke in 1961 ascended to the surface off Key West, Fla., from a depth of 318 feet, a record at the time, using a new escape device.
At Sealab, Mazzone was known as a taskmaster, unwilling to accept anything but perfection, given that lives were at risk.
"He was a tough man to work for — but a good man," said Bob Barth, who worked with Mazzone. "He was fair, honest and direct. Every detail was important to him."
The head of Sealab was Capt. George Bond but Mazzone, with an innate inquisitiveness and a zeal for details, provided the guidance that led to its innovations, according to Ben Hellwarth, author of "Sealab: America's Forgotten Quest to Live and Work on the Ocean Floor," published in 2012.
"Without Mazzone, it's unlikely that Bond would have gotten as far as he did with the Sealab program," Hellwarth wrote recently, "or the advances in diving methods and technology that had a swift and lasting impact on military and civilian diving."
The Sealab tests allowed for advances in how to correct for decompression sickness (the bends) that strikes divers. By testing divers living in undersea habitats, researchers gauged the psychological and physiological impact of dives that were deeper and longer than average.
In 1969, after the death of a U.S. diver, the Sealab program was publicly discontinued but much of the research continued in a classified setting.
In 1971, using innovations pioneered at Sealab, a U.S. surveillance submarine reached the floor of the Soviet Sea of Okhotsk, retrieved Soviet test missiles and installed a tap on a phone cable that gave the U.S. classified information about the Soviet navy.
Mazzone retired from the Navy in 1970 and worked at the Navy's Ocean Systems Center in Point Loma, Calif., for a decade before becoming program manager for Navy contracts at Science Applications International Corp., a defense contractor in La Jolla. He retired from SAIC in 2002.
Mazzone's wife, Lucie Margaret Oldham Mazzone, died in 2012. He is survived by their son; two grandchildren and five great-grandchildren.