SpongeBob SquarePants

For those of you out there, like me, who aren’t in the know, here’s a bit of context. There is a popular television show titled “SpongeBob SquarePants”. The show follows a yellow sponge named SpongeBob who lives in a pineapple in the underwater city of Bikini Village. SpongeBob works as a fry cook at the Krusty Krab. The Krusty Krab is designed to look like a lobster trap, it has a big clam shell sign out front and sports five Maritime Signal Flags above the door.

This is where the controversy begins. I first came across this topic on r/vexillology. I honesty thought that the group would have a more apt community when it came to identifying flags. It certainly doesn’t stack up to the members of the Flags of the Worlds Facebook Group.

A close up of the “signal flags” hanging above the door to the Krusty Krab.

If you haven’t already seen my page on Signal Flags, I’d encourage you to take a look through. Using that list as a guide you’ll be quickly able to identify four out of the five flags, that is, if you’re willing to overlook some minor directional issues.

Let’s break it down and start from the left.


ICS_Romeo.svgThe first flag we see is the flag Romeo. Alone, this flag represents the letter ‘R’.


ICS_India.svgThe second flag is India. Alone, this flag represents the letter ‘I’. In International Code of Signals, India flying alone means “I am altering my course to port”. However, that interpretation means nothing in this case.


We’ll come back to this flag in a little bit, but for now, we know that this flag doesn’t exist in the ICS.


ICS_Uniform.svgSo this is where we start making some assumptions and allowances. Flags are normally hoisted vertically. When hoisted, Uniform’s canton is a red square. By this logic the flags are hoisted such that Uniform is actually the second flag in the sequence. However, this causes further issues with the flags next to it.

Perhaps instead the artist thought of them as being hung in this horizontal manner, meaning that the flags are rotated 90 degrees and this flag is just accidentally mirrored. Perhaps it is a simple mistake, or it just isn’t flag Uniform. But I think we could put this down to a simple mistake that was never revised.

Alone the flag can represent the letter ‘U’, or in ICS, “You are running into danger”. In the context of the show that may have been an intentional or unintentional joke, but I honestly doubt it.


ICS_Kilo.svgAgain, we have to make some concessions and allowances here about the flag’s direction. If we interpret Uniform as the second flag in the sequence as it would have been read from top-to-bottom, then this flag is actually rotated 90 degrees and doesn’t make much sense. Let’s assume that this is Kilo, and put it down to another error.

Alone the flag can represent the letter ‘K’, or in ICS, “I wish to communicate with you”.

The Unknown Flag

apbacautionAll of this still leaves us with a mystery centre flag. According to the International Code of Signals, this flag doesn’t exist.

The American Power Boating Association lists this flag as a Caution signal. There is a problem on the race course and drivers must proceed with caution.

It doesn’t make any sense to mix Maritime Signal Flags with a racing flag.

The British Royal Navy 1940

Last but not least, let’s look at another possibility. Perhaps the artist referenced some outdated material when drawing up the Krusty Krab. Prior to the development of NATO, each navy used their own flag signalling system to communicate between ships. Signalmen had to learn their navy’s code as well as the International Code of Signals, and as you can see, while many of the flags appear in both sets of code their meanings differ greatly. Here is a selection of flags from the British Royal Navy’s flag signal code from 1940.


Referencing this table you may interpret the flags of the Krusty Krab, again providing there may be some simple directional errors, as:

AT-H-FL 7-FL 1-FL 6

  • AT is short hand for “Astern”, meaning behind or towards the back of the ship.
  • H is simply the letter ‘H’ but may contain another meaning when flown alone.
  • FL 7, FL 1, and FL 6 are alternate ways of representing the numbers instead of using pennants. These flags could also have alternate meanings when flown alone.

Again, there is no meaning to be found in this interpretation.

A113 Theory

It is well known that many Disney and Pixar movies contain the text “A113” at some point in the film. It is an inside joke among the alumni of the California Institute of Arts and references a classroom at the school for the graphic design and character animation students.

Some people online have suggested that perhaps ATH 716 or ASH 716 depending on which table is referenced, is an inside joke among the animators of the show. As of yet this hasn’t been linked to anything and is purely speculation.


The more we delve into the meaning of the flags that hang from the Krusty Krab in the fictional world of SpongeBob SquarePants, the less meaning we find. There is not single code set that includes all five flags, and the display of the flags itself is imperfect with the flags that do exist in any one code set. In fact, I would posit that this is the true intention of the creators; use flags that are familiar enough without any actual meaning to both intrigue those in the know and yet not accidentally portray something that could harbour any meaning.