Deliberate mistake: The Seaview's 8 huge picture windows were a concession to design over practicality. Though they knew that such big windows could never withstand deep sea pressures, the producers wanted the characters - and the audience - to be able to see all the underwater wonders "up close." The "impossible" windows became one of the show's most popular features. (00:25:10)
Deliberate mistake: Several of the roaming dinosaur segments here are repeated 2-3 times over. They're all recycled footage from producer Irwin Allen's own 1960 remake of "The Lost World," and Allen must have wanted to get as much use out of the dino shots as possible. (00:28:00)
Deliberate mistake: The huge system and missile control boards containing the failsafe units suddenly appear on Seaview's bulkheads just for this episode. And of course, they disappear after this, never to be seen again. (00:15:00)