Mobilis in mobili
“Moving in the moving element.”
Jules Verne, Twenty Thousand Leagues Under the Seas
What does “Mobilis in mobili” mean?
Mobilis in mobili translates as “Moving in the moving element.”
Free and adaptable, moving within a changing world.
“Mobilis in mobili” word by word
| Latin | English | Grammar |
|---|---|---|
| Mobilis | moving, mobile | nominative singular (masculine or feminine) of the adjective mobilis, “movable, mobile”; agrees with the unstated subject, the one who moves |
| in | in | preposition meaning “in” or “within”, here followed by the ablative case |
| mobili | the moving (element) | ablative singular (neuter) of the adjective mobilis, used as a noun: “the moving thing”; the case required by in when it means “in” |
How to pronounce “Mobilis in mobili”
Both pronunciations sound the same here. Stress the first syllable of both mobilis and mobili.
The story behind it
Word for word the phrase says “mobile in the mobile”, or “moving in the moving”. The adjective is used as a noun in the second place, so the line is usually read as “moving in the moving element”, meaning water.
It is not ancient Latin. It is the motto of the Nautilus, Captain Nemo’s submarine in Jules Verne’s novel Twenty Thousand Leagues Under the Seas (1870). In the book it appears as the motto on the vessel’s fittings.
Since then the phrase has been borrowed for ships, sailing and diving clubs, and as a personal motto for people who want to stay flexible and keep moving as the world around them changes.
How to use “Mobilis in mobili”
A fitting motto for sailors, divers and swimmers, a nautical tattoo, or a personal reminder to stay adaptable when life keeps shifting. It also suits a Jules Verne or Nemo themed gift, card or print.
- Latin
- Mobilis in mobili
- English
- Moving in the moving element.
- Source
- Jules Verne, Twenty Thousand Leagues Under the Seas
- Era
- Modern
- Theme
- Freedom
Common mistakes
- It is not a classical Roman saying. It comes from Jules Verne’s novel, so do not attribute it to Cicero or any ancient author.
- The second word is not a repeat by accident: mobilis (nominative) and mobili (ablative) are two different forms of the same adjective.
- Do not translate it as “mobile in mobility” or “moving in motion”. The second mobili points to a moving medium, the sea.
- Changing the quote for a woman or a group needs care: mobilis stays the same for masculine and feminine singular, but the plural becomes mobiles.
Questions about “Mobilis in mobili”
What does “Mobilis in mobili” mean literally?
“Mobile in the mobile”, usually rendered “moving in the moving element”. The element it refers to is water.
Who said “Mobilis in mobili”?
It is the motto of Captain Nemo’s submarine Nautilus in Jules Verne’s novel Twenty Thousand Leagues Under the Seas (1870). It is a literary motto, not an ancient Roman saying.
How do you pronounce “Mobilis in mobili”?
Classical and church pronunciation match: MOH-bih-lis in MOH-bih-lee, with the stress on the first syllable of each long word.
Is “Mobilis in mobili” correct Latin for a tattoo?
Yes. The grammar is sound: the adjective mobilis, the preposition in, and the ablative mobili. Just be aware its fame comes from Verne’s novel, not from Roman authors.
More to explore
Translation and grammar checked by Latin Quoter · last reviewed November 2026
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