The set for the bad guy's apartment is the same one used for the villain in the previous episode, with very little difference.
The dock seen near the end is the same one seen at the beginning and end of The Miracle (1971) broadcast earlier in this season.
Barney climbing up the elevator shaft was original used in season 3 Doomsday.
French title: "Les diamants sous la mer"
In the tape scene, the photograph which introduces villain Fritz Weaver is the same one used in the season two show "Charity".