The year given for this episode is 1978.
Robert Brubaker (Howard), Stan Kamber (Sailor), Ray Didsbury (Ray), Garrett Myles (Henderson), Robert Johnson (Travis)
As with the episode "Graveyard of Fear" stock footage shows Crane emerging from the Flying Sub into open water, when they're actually right on the sea bed.
The scene of the Flying Sub travelling along a coast is taken from "...And Five of Us are Left". The back view of Kowalski is actually Crewman Werden, looking through the Sub-Terrestrial Scanner. An instant later a front shot of Kowalski shows him with his hands on the armrests and the scanner in his lap.
Brent: Superstition, my dear Captain, is often born in fact.