Mike Kellin portraying the main character, Chief Bell, died 26 August 1983, the ship used for exterior shots in the episode was decommissioned 11 August 1983. Simon Oakland, who portrayed the captain, died three days later on 29 August 1983.
The hull number for the sunken submarine, 714, was not actually used by the Navy until the construction began on the USS NORFOLK SSN714 in August of 1979. In the episode, it was mentioned that the submarine was built in 1941. Those built in 1941 had "21x" hull numbers.