[[caption-width-right:250:Nelson, Crane, and the Seaview]]
A 1964-68 Creator/IrwinAllen SciFi show starring Richard Basehart as Admiral Nelson and David Hedison as Captain Crane, and set on the experimental nuclear-powered research submarine, ''Seaview''. The ultimate use of the RecycledScript: almost every episode can be summarized as "MonsterOfTheWeek is defeated by [[RayGun Laser Of The Week]]." (It should be noted that the first season, filmed and broadcast in black & white, featured more serious and thoughtful stories, along with a greater ColdWar emphasis.) A bit of a wet version of ''Series/StarTrekTheOriginalSeries'' (which it preceded by two years). Compare ''Series/SeaQuestDSV''.
Based on [[Film/VoyageToTheBottomOfTheSea the 1961 film of the same name]], in which our heroes defeat a [[GlobalWarning global heat wave]] (caused by the then recently discovered Van Allen radiation belt [[HollywoodScience catching on fire]]) through DeusExNukina. No, seriously. The movie's storyline was later on recycled as a series episode titled "The Sky's On Fire", complete with copious amounts of StockFootage from the motion picture.
Interestingly, the series switched from black and white to colour during its run, which was used as an excuse for a big dramatic storyline during the switch, and the introduction of a new version of the ship.
* AFormYouAreComfortableWith: The downed alien in "The Sky is Falling" is quite ugly by human standards. So, when talking to Admiral Nelson, it takes on a form it feels Nelson wouldn't find offensive: [[spoiler: that of Nelson, himself. And it later does the same for Capt. Crane.]]
* AIIsACrapshoot: Averted in "The Human Computer". The Seaview's new ship-controlling computer system works fine. It's the enemy saboteur on board that's the problem.
* AirVentEscape: Played with in "The City Beneath the Sea", where plugging up an air vent, rather than crawling through it, leads to Crane and the GirlOfTheWeek escaping.
** Played straight in many episodes afterwards.
* AliensInCardiff: Aliens invariably invade the ''Seaview'', and only the ''Seaview'', instead of [[TokyoIsTheCenterOftheUniverse Tokyo]], [[BigApplesauce New York]], or other such places that aren't isolated arenas several leagues under the sea.
* BaldOfEvil: Most of the members of the villainous group in the pilot ("Eleven Days to Zero") sport this.
* BrainwashedAndCrazy: Both being brainwashed to kill your friends and being almost killed by your brainwashed friends were consistent threats on the ''Seaview''. Practically once-an-episode consistent.
* BodySnatcher: If it wasn't brainwashing, the other ever-present threat was having your body taken over by malevolent aliens/ghosts/etc. Captain Krueger's use of this trope is probably the show's best example, since [[http://www.vttbots.com/classic_phantom.html "The Phantom Strikes"]] was well-received enough to warrant a rare sequel, "The Return of the Phantom".
* ColdWar: Several episodes, especially in the first season, use this as a backdrop.
* CoolBoat: The flying submarine, as well as the ''Seaview'' itself.
* CoolPlane: The flying sub, introduced in the second season.
* DroppedABridgeOnHim: In "Eleven Days to Zero", the original pilot, the narrator introduces the original captain of the Seaview, John Phillips. Phillips is shot dead less than five minutes later.
* FailSafeFailure: In the first season episode "Doomsday".
* FramedFaceOpening: Used in the TitleSequence from the second season onwards.
* GagDub: Episode "Werewolf", where one of the protagonists is infected with a germ that turns him into a werewolf with the reactor core's radiation, was famously gag-dubbed by Mexican comediant Trino into the protagonist "getting" AIDS in the hand from Captain Patterson, going to the reactor core to take a dump believing it's the restroom, and transforming into a monster from the AIDS.
* HeroesRUs: The Nelson Institute of Marine Research.
* HisNameIs: In "Secret of the Loch", Scotland Yard Inspector Lester radios Nelson and Crane that he's found out the truth of what's going on at Loch Ness. And he's killed by [[spoiler: the fake Nessie]] just before telling them the rest.
* MildlyMilitary: The ''Seaview'' technically belongs to the NIMR, but the crew is comprised of civilian and Navy personnel. They're at the government's beck and call, which is presumably why they're trusted to pack nuclear missiles and single-handedly guard the world from undersea Communists and space Nazis.
* NotTheNessie: TheReveal of [[spoiler:"Secret of the Loch".]]
* TheRemnant: One episode dealt with a Japanese holdout from UsefulNotes/WorldWarII.
* ScrewTheRulesImDoingWhatsRight: Missile officer Corbett does this twice in "Doomsday". First, he can't bring himself to turn his missile key when a war alert is sounded. Then, [[spoiler: he refuses to set a missile to explode beneath the ocean's surface, which would keep the episode's FailSafeFailure secret from the public.]]
* SpiritualSuccessor: ''Series/SeaquestDSV''.
* StockFootage: Lots. "Creator/IrwinAllen" is basically synonymous with this trope.
* TwentyMinutesIntoTheFuture: The series was set during TheSeventies, roughly a decade ahead of when it was made.
** "Doomsday", from the first season, sets the year at 1973.
* WithGreatPowerComesGreatInsanity: An early example is Jenkins from the first season episode, "The Amphibians". Experiments give him the ability to survive underwater, along with heightened senses and strength, and makes him power-mad.