- French narrator
- Gary the Snail
- SpongeBob SquarePants
- Patrick Star
- Squidward Tentacles
- Monroe Timmy
- Sandy Cheeks
- Eugene H. Krabs
SynopsisAt SpongeBob's house, and Patrick and SpongeBob are dancing. The music is shaking Squidward's house, so Squidward becomes annoyed and rudely requests to SpongeBob to lower the volume. When they do not listen, Squidward plays a squeaky tune which sends SpongeBob and Patrick flying into Squidward's house and causes SpongeBob to hit Squidward, lodging his clarinet in his throat which makes Squidward make squeaky notes. When SpongeBob gets the clarinet out of Squidward's throat the reed is still stuck in him and Squidward blames SpongeBob. They then go to Sandy who has a plan. She decides to go in a submarine, shrink herself (and the submarine), go into Squidward's body and retrieve the reed.
When Sandy goes to get some acorns and nuts from the Treedome she tells SpongeBob to guard the submarine. Patrick walks by and tricks SpongeBob into guarding the submarine from the inside. They go in there and guard it when Patrick presses the shrink button, shrinking the submarine. Sandy comes back and notices them. She then has to guide them to Squidward's brain. There, SpongeBob and Patrick start to hit parts of the brain, making Squidward lose self-control.For a moment, SpongeBob and Patrick actually fight each other for control of the vehicle and land in Squidward's stomach, where the gastric acid starts to eat the submarine away. Patrick thinks of an idea: If Squidward can drink soda, then bubbles (gas) would surround them and it would refuel the submarine. Squidward drinks soda and the suddenly burps creating bubbles. They travel through the throat where SpongeBob removes the clarinet reed by doing what he was "born to do," dance. The reed is removed and the gang celebrates, but is cut short by the sound of the now angered Squidward. He demands them to leave his body and yells at them to "GO!" However, Patrick mistakes it for "grow" and hits the grow button while still being in Squidward's body.
Squidward is next seen at the Krusty Krab looking bloated and his stomach in the shape of a submarine. A flush sound is then heard, followed by Patrick, still stuck in the submarine in Squidward's body, claiming the toilet is clogged (again, apparently) Squidward groans.
|( ‣ ) Associated production music|
|( • ) Original music|
|( ◦ ) SpongeBob music|
‣ Maui Girl - Harry Bluestone [title card]
‣ SpongeBob Rocks the House - Nicolas Carr [opening]
‣ ? - Nicolas Carr, Barry Anthony [Squidward playing clarinet]
‣ Dramatic Impact 2 - Ivor Slaney [SpongeBob slams into Squidward]
‣ Vibe Q Sting - Nicolas Carr ["Oh."]
‣ Tension Bits - Nicolas Carr, Sage Guyton, Jeremy Wakefield [SpongeBob trying to get the clarinet out of Squidward's throat]
‣ The March of the Ants - Sidney Crooke [x-ray of Squidward's throat]
‣ Haunted - Rick Cassman, Vyv Hope-Scott [Sandy's submarine]
‣ Steel Sting (d) - "Always wanting to do it the hard way."
‣ Nude Sting - Nicolas Carr [Sandy knocks Squidward out]
‣ Vibe Sting - Nicolas Carr ["Oops!"]
‣ Fanfare (b) - Nicolas Carr ["Can do, Sandy!"]
‣ Planet Surface - Gregor F. Narholz [Submarine opens up]
‣ ? - Nicolas Carr ["SpongeBob and Patrick reporting for guard duty."]
‣ Cream Pie - Sage Guyton, Jeremy Wakefield [SpongeBob, Patrick enter the submarine]
‣ Project X - King Palmer [submarine shrinking]
‣ Secret Shadow - John Scott [submarine put into Squidward's nose]
‣ Lovely Scenery (c) - Mladen Franko [Squidward screams]
‣ Cosmic Cloud - Trevor Duncan ["SpongeBob and Patrick are piloting a miniature submarine inside my head?!"]
‣ Project X - King Palmer [Squidward panicking]
‣ Weird Bridge - Roger Roger ["Where are we, Patrick?"]
‣ Drama Link (f) - Hubert Clifford ["I'll save you, Sandy!"]
‣ Moon Walk - John Fox [submarine breaks down]
‣ Dramatic Cue (c) - Ronald Hanmer [SpongeBob floors it]
‣ Missile Disaster - John Fox [submarine stuck in Squidward's brain]
‣ Steel Licks - Jeremy Wakefield ["Oh, just your autograph."]
‣ On Fire - Gregor F. Narholz [Squidward hitting himself]
‣ Danger Force - Norman Dane [submarine lands in Squidward's stomach]
‣ Exciting Action (b) - Mladen Franko [Squidward burps]
‣ Missile Disaster - John Fox ["Whee!"]
‣ Lap Steel - Nicolas Carr [Sandy smells Squidward's breath]
‣ Danger Force - Norman Dane [Squidward's esophagus]
‣ Flashback - Nicolas Carr [two hours later]
‣ Danger Force - Norman Dane ["This stupid hammer won't break anything."]
‣ Wild Panic 30 - Gregor F. Narholz ["Whirlpool spin!"]
‣ Steel Sting - Jeremy Wakefield [Squidward coughs up the reed]
‣ Vibe Sting - Nicolas Carr ["Grow?"]
‣ Drama Link (b) - Hubert Clifford [everyone screams]
‣ The Tip Top Polka/The Cliff Polka - Chelmsford Folk Band [The Krusty Krab]
‣ Drama Link (f) - Hubert Clifford ["Neptune's trousers!"]
‣ Drama Link (d) - Hubert Clifford ["Neptune's trousers!"]
‣ The Tip Top Polka/The Cliff Polka - Chelmsford Folk Band ["What's gotten into you?"]
‣ Captain Lenoe's - Michael Arthur, Colin Cater, Mick Graves, The Folk Players, Sarah Graves, Simon Ritchie [ending]
- This episode is available on the Season 4 Volume 2, Complete Fourth Season, and First 100 Episodes DVDs.
- As of February 27, 2017, The Internet Movie Database (IMDB) gives this episode a rating of 7.5/10 based on 179 ratings by users. TV.com users give this episode a rating of 8.3/10 based on 129 votes.
- The beginning of the episode is similar to the main plot of "Jellyfish Jam," in that SpongeBob's loud music makes Squidward angry.
- SpongeBob makes a reference to "SB-129" when he says, "Squidward! You swallowed your clarinet again!" This also breaks the fourth wall.
- This is the second time Squidward swallows his clarinet. The first was in "SB-129."
- This is the first episode where Squidward enters Sandy's treedome.
- This is the first time SpongeBob and Patrick go inside Squidward's body. The second would be in "Snooze You Lose."
- When the micro-submarine is bouncing inside Squidward's skull, the blue sparks are pizeoelectricty, the body's electricity.
- SpongeBob drives a submarine again in the episodes "20,000 Patties Under the Sea" and "Hide and Then What Happens?"
- In the near end of the episode, there can be seen a roof above the kitchen/office area behind where Mr. Krabs is standing painted green. This does not appear in any other episodes.
- It is also the color of the floor of the Krusty Krab.
- This episode aired on YTV on April 11, 2007, during an event called SpongeBob Wednesday Pants.
- In the UK, this episode is sometimes paired with "Chimps Ahoy."
- In the Hebrew dub this episode is called "יום בתוך סקווידוויד" translating to "Day inside Squidward."
- In the Greek dub this episode is called "Ένα καλαμαρένιο ταξίδι" translating to "A Squid Trip."
- This episode must set before "20,000 Patties Under the Sea" as Patrick states he's never been in a submarine.
- Nickelodeon Poland mistakenly aired this episode on March 4, 2014 with English audio track instead of Polish audio track.
- The title card BG is like the part when SpongeBob and Patrick enter Squidward's Brain except without the sub.
- An online game based on the episode can be played at SpongeBob.com
- This is the first episode to play the Tension Bits.
- The title and plot of this episode is a reference to the 1966 film "Fantastic Voyage," and it also parodies the 1987 film Innerspace.
- SpongeBob using the Whirlpool Spin to slice apart the reed is similar to the climatic battle in the 1983 anime show Ginga Nagareboshi Gin, where the titular dog decapitates the demon bear Akakabuto with the Zetsu Tenrou Battouga.
- In reality, the mouthpiece was the piece stuck in Squidward's throat. The reed is attached to the mouthpiece which vibrates to make a sound out of an instrument. The reed is also a brownish-yellow and not black, which is the color of the mouthpiece.
- When SpongeBob says "Whirlpool spin!" his mouth does not move The same error occurred in "Squirrel Jokes."
- In the first scene of the submarine, it looks like it is on an open platform, but later starting in the scene with SpongeBob guarding the submarine, it looks like it is in a room.
- When SpongeBob and Patrick are saying "Whee!" in the submarine, SpongeBob blinks his eyes but his eyelashes are still seen.
- When Squidward burps, Sandy smells it even though she is wearing a helmet. However, she should not be able to because of the helmet on her head. In "Karate Island", she could not smell Filthy Phil's body odor.
- When SpongeBob cuts the reed in half, red electricity is randomly seen for less than a second.
- Comcast claims that this episode and "That's No Lady" first aired December 1, 2006.
- Squidward cannot stop making clarinet noises in the beginning because he swallows the whole clarinet at first, yet he can speak just fine in Sandy's submarine lab.
- Closed-captioning error: when SpongeBob and Patrick are dancing at the beginning, SpongeBob says, "Tropical breeze!" However, the captions said "Tropical waves" instead.