I served on submarines in the US Navy during the cold war. John P. Craven, a former Navy scientist whose innovations in ocean technology and exploration led to some of the nation’s most celebrated feats of espionage, died on Feb. 12 in Hawaii. He was 90. The cause was complications of Parkinson’s disease, his family said.
From 1959 to 1969, as chief scientist of the Special Projects Office, Dr. Craven led the Navy’s drive to expand its presence into the crushing depths of the sea. Among other things, he turned submarines into spy machines that could reach down miles to inspect and retrieve lost enemy matériel, including nuclear arms.