Raymond Burr served in the United States Navy during World War II. While in Okinawa, he was shot in the stomach and sent home.
The submarine seen in this episode, the fictional USS Moray, was in reality the USS Sawfish SS-276. USS Sawfish was a Gato class submarine commissioned in 1942. Sawfish served in combat in the Pacific during World War II and received 8 Battle Star awards. At the time this episode was filmed, Sawfish was based at San Pedro and was used to train Naval Reserve personnel. Shortly after being used for filming, Sawfish was decommissioned and stricken on April 1, 1960, after which she was scrapped.
At the end of this episode, Paul makes a joke about traveling the world, and Perry suggests that he join the Navy. Both Raymond Burr and William Hopper served in the Navy during World War II.
William Hopper (Paul Drake) served in the Navy in the Pacific. He was an underwater demolition team (UDT) member.
When the detail escorting Chapman disembarks, the name of the neighboring submarine, USS Swordfish SS-276 is in view. The submarine USS Swordfish SS-193 was lost somewhere near the the Ryukyu Islands, 12 January 1945, perhaps by a mine near Okinawa Harbor. The designation SS-276 was actually the USS Sawfish. The sign on the gangway to the Moray reads SS-301, which is the designation of the USS Roncador, a Balao-class submarine, which may have been used for filming the shore and on-deck shots adjacent to the Sawfish.