A fairly common feature in near-future works is cities built on artificial islands in the middle of the ocean. Often they are built to alleviate overcrowding on land, especially when Global Warming
causes sea levels to rise and envelop coastal cities, but just as often they are sites for Mega Corps
to do things that may or may not exactly be "legal" in most conventional nations.
Related to Underwater City
, which is when the colony is under the water instead of on it.
- Ghost in the Shell 2 (the manga) features Poseidon Industrial's artificial island city, where Motoko "Aramaki's" real body is typically located.
- The second film has an android producing corporation that bases their factory on a ship because they're dubbing the ghosts of young girls into their robots
- In Waterworld since all known land has been covered by water most people live in "atolls" made from scrap metal. As well as traders who live on boats and the "smokers" who are based on the Exxon Valdez.
- In Star Wars, the populace of the water-world Mon Calamari live in giant floating cities. One half is above water for the Mon Cals and air-breathing visitors, one half underwater and flooded for the Quarren.
- David Brin's novel Existence has artificial islands popping up as sea levels rise. However most of them are resorts for the super-rich or havens for questionably legal biotech experiments. China has a "shoresteading" program for desperate people to try and make the upper levels of flooded mansions in what used to be Shanghai liveable.
- Gordon R Dickson's Home From the Shore
- The Undersea Trilogy by Frederik Pohl and Jack Williamson was one of the first in-depth explorations of the undersea domed city concept.
- Neal Stephenson's Snow Crash has "Rife's Raft", a gigantic, cobbled-together collection of floating garbage in the Pacific Ocean inhabited by huge numbers of refugees, mostly from Asia.
- David Drake's The Lord of the Isles series includes a vignette in the first book in which Sharina, Nonus, and some useless nobles spend a few days on the Houseboats of the Sea People. They spend their entire lives at sea and live in large structures crafted largely from whale.
- Nineteen Eighty-Four repeatedly mentions military installations called "floating fortresses" that are apparently under construction, but never explains what they are.
- In Raiders of Gor we meet the Caste of Rencers, who live in a delta connecting a great river and the sea, gathering rence[[labelnote:a multi-purpose plant used for making paper, rope, utensils, cloth, and food]] for trade. They live in small villages built on floating rafts of rence. As the rence rots away underwater they weave new layers on top.
- The Skeezers in ''Glinda of Oz'' live in a city suspended the middle of a lake. In times of danger they can magically submerge the entire city for protection, turning it into an Underwater City.
- Classic Traveller supplement The Traveller Adventure. The planet Heguz is an Ocean Planet. It has had two colonies, both set up on large floating bases. Both colonies mysteriously disappeared without a trace.
- A major gameplay element of Sid Meier's Alpha Centauri, as any faction can create sea based settlements as well as the standard land based ones, in contrast to the Civilization series where only land based cities are permitted. The Nautilus Pirates faction starts the game with such a settlement and can create an ocean empire faster than the others.
- Frequent in RTS games that involve naval combat (most Command & Conquer titles, for example): the ship-building structures are constructed directly at sea.
- Brink is set aboard The Ark, an experimental floating colony designed to be completely self sufficient.
- Knights of the Old Republic has the planet of Manaan with the native water-breathing Selkath, which is covered entirely with water except for Ahto City, which is built on the surface of the ocean to accommodate visitors.
In Final Fantasy X, during the Shoopuf ride you learn about the city built over the ocean, which was built just because it could be. Needless to say, it got destroyed by Sin and sank to the bottom.
- S.S.D.D has the Britannia, a massive ship built on an iceberg that England's wealthy fled to when the Anarchists took over.
- In The Kenny Chronicles Tarnekis, genetically engineered human-animal hybrids are largely forced to live on converted cruise ships. The sequel series, Ferrets vs. Lemmings takes place on an artificial island.
- Certain groups such as The Seasteading Institute and Project Blueseed intend to do this in real life.
- The unrecognized micronation Sealand is based on one of the Maunsell Sea Forts built during WWII.
- Frequently seen in nations with sea access and not enough space for new buildings (Japan, Singapore... etc.) as well as countries with an influx of wealthy tourists and investors (Dubai, Bahrain...).