- Adaptation Displacement: Especially considering that the original Sealab 2020 was a flop.
- Big-Lipped Alligator Moment: Quite a few, but especially the "Uh-oh" sequence.
- Bizarro Episode: Strangely has nothing to do with the episode titled "Bizarro". "7211" may count for being the only non-comedic episode in the series. It was redubbed by the 2021 actors, but using the 2020 script, just to show how boring the old show was.
- Crosses the Line Twice: They're good at this.Sparks: Go roll over for the Nazis!Yost: For your information, the Dutch Resistance was a crucial factor in the Allied victory in World War II.Sparks: Oh yeah? Why don't you go tell that to Anne Frank?
- Ensemble Dark Horse:
- Captain Murphy. There's a reason that many people consider the episodes after he was written out of the show to be inferior. He was so popular that the fourth season finale of Archer was a tribute to the character.
- The Bizarros. They only appeared in a single episode, but it was arguably the most memorable episode of the series. Bizarro Quinn seems to be an Ensemble Darkhorse among the Bizarros.
- Ear Worm: The theme song is surprisingly lyrical and catchy as all hell.
- Fridge Horror: The Other Wiki lists the ranks of the main characters where known. Guess who had the highest command after Murphy/Shanks (and presumably had control of Sealab when they're between captains)? Sparks. (He's a commander, the others are either lieutenant commander or lieutenant.) Granted, he's one of the non-stupid characters. He's just also insane and evil.
- Hilarious in Hindsight:
- Murphy established the Knights of Mars before they were cool.
- The "Black Stormy" question from "Chickmate" becomes this when we find out the crew of Spacelab are opposite race versions of the Sealab crew. So yes, there is a Black Stormy.
- Idiot Plot: Since nearly all the characters are indeed idiots, a Justified Trope.
- Memetic Mutation:
- "I'm helping! I'm helping!"
- RESPEK KNUCKLES
- Positive Discrimination: Frequently played with with Debbie Dupree (only main female character) and Dr. Quinn (only main African-American character); the show will set them up for this trope, then suddenly have them grab the Idiot Ball or show Jerkass tendencies in order to lampshade the trope. Usually happens to minor recurring character Debbie Love as well.
- Replacement Scrappy: Many fans view Tornado Shanks as this, especially considering he never really had a consistent personality.
- Ugly Cute: Bizarro Quinn, and Murphy's scorpion Ben.
- Uncanny Valley: The "new" animation can often fall into this.
- "Weird Al" Effect: Really, if it weren't for this show, no one would even know there was a Sealab 2020.
- The Woobie: Even though his suffering is almost always Played for Laughs, it's really hard not to feel bad for Quinn.
YMMV / Sealab 2021