The theme music changes quite a bit from previous seasons, including louder, more energetic drums and brass throughout. Guitars are toned down.
In one scene, Mondrago tells McGarrett to "go fight other windmills". This is in reference to Miguel de Cervante's Don Quixote, who in the story fought windmills.
A copy of the Honolulu Advertiser shows a headline in lower case type: "moon landing still in doubt", with the subhead: "hinges on firing of rocket".
Guest star Jeff Corey had the previous year played one of the mutant humans against the ape society in Beneath the Planet of the Apes (1970). Guest star France Nuyen would two years after this play one of the humans against the apes in Battle for the Planet of the Apes (1973).
The introduction to this show was an excavation on a beach and at a supposed lava tube. It was filmed at Mosquito Cove where the love scene in the 1953 film "From Here to Eternity" was filmed.