Space Is an Ocean



"When ships to sail the void between the stars have been invented there will also be men who come forward to sail those ships."

- Johannes Kepler

Maybe it's the romance, maybe it's the adventure, maybe it's the obvious parallels to the Age of Exploration, but for some reason, when people write about space, they tend to make parallels to the sea, as President Kennedy (himself a former naval officer) did in his "Space is the new ocean" speech. Often, it goes far beyond metaphor. Science Fiction writers frequently use nautical analogies for pretty much everything in space, and fill in the gaps in their own knowledge about spaceflight with details specific to sea travel.

This trope also ignores the origins of the analogy. 19th century physics stated that celestial bodies existed within a pseudo-liquid called the luminiferous aether which we simply did not have the technical skill to directly detect at the time. We later discovered that the reason it couldn't be detected is because it doesn't exist. Hence the beginnings of maritime comparison and analogy. (By the way, this wasn't because they were stupid back then and couldn't imagine empty space—it's because they were sure light waves needed something to propagate through. As it turns out, they don't.)

For example...
 * Spacecraft are called "ships". In many series, a small craft can even be called a "boat", and space-based missiles are called "torpedoes".
 * Furthermore, the classes of ships in the Standard Sci-Fi Fleet are usually analogous to classes of waterborne ships, especially those used during World War II: Cruiser, Battleship, Destroyer, Frigate, etc. Good luck finding a Space Schooner or Space Junk.
 * Spacecraft even have "lifeboats" except that they are generally called escape pods or something similar - despite the concept being largely impractical in case of realistic space travel.
 * Some works of fiction blur the line between spaceships and oceangoing vessels even further.
 * Navigation lights, which tell a viewer nothing about the orientation of a ship in zero-g.
 * Space is two-dimensional.
 * Which plays into the fact that viewscreens are almost always two-dimensional, when displays for battles at least should be three.
 * This is probably a result of humans being surface-dwelling creatures—3 dimensions is second nature to us, unlike birds, to whom it's first-nature.
 * Space has friction.
 * Space militaries almost always use naval ranks, and soldiers stationed in space are usually called "marines"; e.g. the "space marines" of Alien, Doom, Marathon, StarCraft, etc. Starship Troopers did not call its soldiers marines though it could be argued that it established the archetype for later space marine forces.
 * It is worth noting NASA itself is not a military organization, and while many astronauts have a military background they can be from any service. Of the first two men on the moon Neil Armstrong flew for the Navy in Korea and retired well before joining NASA, while Buzz Aldrin was Air Force and still commissioned during Apollo 11. Confusion often arises as the military operates its own space ventures within more than one branch, the US Navy for example relies on satellite communications.
 * As a point of reference, both the U.S. Marine Corps and the British Royal Marines actually use the same officer ranks as their respective Army. The U.S. Navy and almost all others have their own officer rankings, and these differ from the other armed forces (e.g. a Navy Captain outranks an Army Captain even if he isn't in command of a specific ship). The Royal Air Force and most of their Commonwealth cousins, meanwhile, use their own unique system based on Army and Navy ranks (Flight Lieutenant, Wing Commander, Air Marshal, etc.)
 * Countries in the Sinosphere (China, Japan, either Korea, Vietnam) don't usually have branch-specific ranks—a Japanese or Chinese "Colonel" is literally a "Land Senior Field Officer" (or "Air Senior Field Officer", for the equivalent of an Air Force colonel), while his naval counterpart is a "Sea Senior Field Officer".
 * Spaceships have a bridge with a big window in the front that looks out on space and is usually at the front or top of the ship. The decks of the spaceship will be parallel to the direction of flight.
 * Spaceships have a very noticeable "top" and "bottom". Cockpits, conning-towers, communication dishes, weapons etc. will mostly be on the "top". The underside will be smoother, often punctuated only by a "bomb-bay" style docking hatch. This could justified for vehicles designed for atmospheric flight and landing, but makes no sense for orbit-to-deep-space-only ships.
 * Space is chock full of whales (and a turtle).
 * A spacecraft can be caught in an "ion storm" or the like, which will toss it hither and thither and ultimately run it aground on a strange exotic uncharted island planet.
 * Space Clouds can hide your ship like an ocean fog.

Slightly more savvy writers may also incorporate elements of atmospheric flight, especially when dealing with single-man craft: Fighters are almost always aerodynamic, and ships will bank when turning if the budget allows. World War II is a common inspiration, with the destroyers, cruisers, battleships and carriers analogous to their nautical namesakes and the fighters to aircraft, using the tactics of Old School Dogfighting and having to close to broadside range with capital-ship guns. Elements of road vehicles are generally Played for Laughs; if a spacecraft has a manual transmission, it's a sure sign that Rule of Funny is a prime consideration.

Somewhat Justified Trope, however, since seafarers long ago evolved the organizational techniques necessary to safely operate a self-sufficient vessel in a potentially hostile environment for an extended period of time, so there may well be reasons to adapt some nautical administrative and logistic features (and the terms for them) instead of inventing everything from scratch. In addition, space vessels would probably have more features in common with ships than aircraft—an aircraft can't simply shut down its engines and drift (at least, not for long) and battleships are the biggest, most mobile, and of course, most common vehicles with multiple large caliber guns on the deck. The widespread "space fighters" concept, though "flawed" in the eyes of certain sci-fi fans, does provide a convenient shorthand method of conveying a sense of action to audiences already familiar with aerial combat.

It is also worth noting that aviation already draws much of its vocabulary and tradition from nautical traditions. The last time you flew on an airliner, you might have noticed the pilots wearing Navy-style uniforms, with the Pilot In Command being stylized as "The Captain". Flight Attendants used to be called Stewardesses, in reference to the Stewards that used to look after passengers on liners (and The Captain, on older warships). Even parts of the airplane like the cockpit, cabin, and rudder, all draw their names from parts of ships. It stands to reason that space travel might go on to draw much of its terminology and tradition from sailing and aviation. After all, the word "Astronaut" is derived from the word "Nautical".

In Space Opera and Science Fantasy and Steampunk Fantasy genres, writers are fond of filling Space with aether streams and solar winds, even magical ships with sails that literally "sail" through the Void. In those cases, you may find you can even breathe in Space. Vacuum? What vacuum? Characterization may also come straight out of the archetypes created during the era of Wooden Ships and Iron Men as well, including intrepid explorers, Cult Colonists, and the aforementioned Space Pirates.

Lots of speculative fiction in all media depict spaceships designed to land on water, since an ocean provides what amounts to an infinite runway. Some examples include the Bebop from Cowboy Bebop, the Seeker from David Brin's Startide Rising, most of the Space shuttles in Jerry Pournelle's CoDominium series, and the actual Apollo spacecraft sent to the moon (as well as the Mercury and Gemini spaceships that preceded Apollo).

Finally, while not technically Truth in Television this trope may well become so out of sheer cultural inertia. If it didn't as soon as NASA started naming space shuttles right out of maritime tradition. There's even a test shuttle named Enterprise (though that is a case of Defictionalization).

Compare Mohs Scale of Science Fiction Hardness, The Sky Is an Ocean, Sand Is Water and Water Is Air.

Anime and Manga
"- The Chouginga Dai-Gurren is going to sink! - Sink? This is space! Why would there be an ocean in space?! - It seems that the waves of ultra-dense space are pushing us down!"
 * Infinite Ryvius takes this further still; the series takes place after the Solar System is given a Negative Space Wedgie. The result is the "Sea of Gedult" (Misspelt German word "Geduld" meaning "patience" in English), a nebula-like cloud engulfing the bottom half of the ecliptic plane. Ships that go too far -- "deep", you might say—inside are crushed by the radiation and gravity anomalies, unless they're built to withstand the "dive". In other words, submarines in space.
 * While Mobile Suit Gundam mostly avoids this territory (or goes to great lengths to justify it), White Base still has a big, old-fashioned and suspiciously nautical steering wheel on the bridge. The same goes for both the Musai-class cruisers and Gaw-class carriers.
 * Deserving special mention is Crossbone Gundam, which has no less than two different ships designed to look like galleons, the Mother Vanguard and its sister ship, Eos Nyx. There's a seeming justification in a later manga, where one character says "Well, if we're going to be Space Pirates, we might as well run with the theme!", but the fact is that Mother Vanguard was designed by an entirely separate faction, one that tended to be aristocratic and knightly rather than piratical.
 * Avoided completely with Gundam Wing, for all of the talk about indestructable Gundams, there was little to no space warships (except for fragile Mobile Suit Carriers which did not pack much in the way of aramaents) and Mobile Suits attacked from Space Stations and Asteroids.
 * The anime OAV Sol Bianca takes this one step further, in that the titular ship enters and exits hyperspace like a submarine diving or surfacing, complete with waves.
 * Super Robot Wars: Original Generation used Army ranks, while using terms that seem to be a combination of nautical and atmospheric flight along with some new ones. This could easily be explained by the fact that star travel is still really quite new—they have some orbital colonies, a base on the moon, and a space station in the asteroid belt.
 * Tengen Toppa Gurren Lagann, where the Cool Starship suddenly sinks into a literal space ocean.

- Yeah. Like I said. WHY THE HELL ARE WE SINKING IN SPACE?!


 * In this case, it was supposedly space so condensed that it acted like water. This included things like pressure. In fact, when that pressure resulted in the super-condensed space punching holes in the hull and "flooding" the ship, they decided that it was more accurate to call it "spacing" than flooding.
 * This might actually be a case of Truth in Television, supermassive black holes (such as the one believed to be at the center of the Milky Way) are theorized to have a density close to water.
 * Leiji Matsumoto provided some of the most literal examples of this trope known to anime, as well as some of the oddest subversions.
 * Space Pirate Captain Harlock is steeped in nauticality: the main title song references the "Sea of Space", the titular space pirate's ship Arcadia has a sterncastle, with a Skull and Cross Bones pirate flag hung above it. The ship is steered with an old-fashioned wooden steering wheel, and Harlock has, on occasion, sailed her on and below an ocean.
 * Harlock's friend Emeraldas' ship Queen Emeraldas is a literal ship, suspended from a zeppelin.
 * In Uchuu Senkan Yamato, Earth deliberately refits old (as in WWII-vintage) battleships as starships, and even continues to paint anti-fouling paint on them below the "waterline." The paint, however, makes sense, as the ship is intended to still function on water.
 * Almost all the space combat is two-dimensional as well until a battle in Season Three where the Yamato attacks from below the plane of battle, spinning on its fore-to-aft axis to shoot enemies on all sides.
 * The same thing happens in Gou Gou Sentai Boukenger—The GoGoVoyager is a (VERY large) battleship which, naturally, reconfigures into a giant robot, DaiVoyager. At the end of the series, GoGoVoyager has been converted into a spaceship... quite badly, if the cockpit is any indication.
 * In Galaxy Express 999, and The Galaxy Railways, though, space is a railway.
 * In Starship Operators, the ships are on the same scale as battleships and (usually) fight like battleships. Two "stealth ships" are called "space submarines". Whenever any ship is destroyed, it's reported as having been "sunk".
 * The opening in Outlaw Star gives a narration in most episodes heavily relating space to being an ocean. Also in one episode their ship rides a stream of aether through space.

Comic Books

 * Taken very literally in an early issue of Fantastic Four. There's only time to send one of the Inhumans to rescue Reed, who's stuck in the Negative Zone; Black Bolt chooses Triton, the merman, because space is like an ocean.
 * Recurring X-Men allies The Starjammers fit this trope.
 * The French graphic novel series, HK has the submarine route, as spacecraft here look like giant robotic whales and sharks. Whilst we don't see them battle each other, their decks are arranged in parallel like a submarine, and they land in bodies of water at harbors.

Films

 * Parodied on Back at the Barnyard. Otis and Pip are in outer space, with no idea of how to pilot the space shuttle they are in. Pip makes a remark about how, "that ship has sailed." Otis acts as if this reference to ships gave him an idea, saying, "Wait a minute? Ship? Sailing?" But then he admits, "No, never mind, I've got nothing."
 * Star Wars (Though to be fair, many of the films' space battles would be incomprehensible if they took full advantage of 3D space.)
 * Where the concept is taken to its reductio ad absurdum endpoint in Attack of the Clones where Obi-Wan Kenobi is forced to dodge seismic charges (read: depth charges) that make a loud "sonic" boom in a vacuum.
 * The space battle which opens Star Wars Episode III: Revenge of the Sith takes this to an extreme, with kilometres-long spaceships side by side, firing broadsides at each other like ships of the line from the Age of Sail. Any doubt as to what the scene was trying to evoke was removed when you saw the gun crews loading and firing their giant blaster cannon through force-field gun ports.
 * In Return of the Jedi when Rebel vessels and Imperial Star Destroyers trade blasterfire during the final climactic space battle, with fighters streaming past in the foreground.
 * Star Destroyers seem to array most of their guns in a top-turret and broadside position, making them commically vulnerable to anyone coming in from behind or below them.
 * The movie Treasure Planet takes this trope to extremes, with spaceships that have big honking sails on them. While solar sails are in fact a reasonably scientific idea, they probably wouldn't be slung on masts of craft which were basically spacefaring galleons, leaning instead towards thin sheets, many hundreds of kilometers across, designed to catch particles of the solar wind reflect photons. The characters are not in outer space in those ships, but rather in a kind of backwards universe where normal physics do not apply uniformly.
 * There's even a black hole that's treated as a whirlpool.
 * Also, the "solar sails" in the movie act more like ridiculously efficient solar panels than actual solar sails; the ship's propulsion is actually provided by engines mounted at the stern. The sails don't propel the ship directly, they just provide power to the engines, and probably the artificial gravity and the other stuff that requires electrical power.
 * WALL-E. The Axiom's autopilot, who is literally the ship's steering wheel, turns so that the ship tilts and everybody slides across the floor. Also, the captain is dressed similar to a sailor.
 * In BURN-E it is revealed that the ship had actually tilted several degrees to one side. Not that it makes much sense, but it was pretty cool.
 * The film version of Wing Commander, ridiculously bad as it was, did do an interesting variation on this trope. In it, space was like an ocean, but spaceships were more akin to submarines than sailing ships (to the point that the crew was told to make no noise to avoid detection). Missiles had to be loaded into great honking tubes after the auto-loaders were said to have broken down from battle damage, they had depth-charge-like weapons.
 * Additionally, the missiles had to be fired manually by the loading crews on command from The Bridge instead of a single button on said bridge. Interestingly, the final space battle between the Tiger's Claw and a Kilrathi battleship ends up looking more like a surface naval battle with.
 * The Space Fighters, though, looked more like World War Two fighters with a computer and a HUD and wouldn't look out of space with propellers on the front. They also, for some reason, include jump drives, even though they're never expected to perform jumps.
 * Oh, and their on-board computers appear to have tons of data, including the identities of top-secret high-ranking operatives. The Kilrathi should've been trying to capture one of those computers instead of a Navcom AI.
 * This Island Earth. Even the title is an example.
 * Actually, during the space travel scene, the alien UFO does a very non-nautical manuever to dodge an asteroid, tilting right 90 degrees while gravity inside the ship remained the same.
 * Walt Disney's movie The Black Hole is a version of Jules Verne's classic novel 20,000 Leagues Under the Sea set in space.
 * Although, to be fair, the Palomino was portrayed as a vertically-arrayed vehicle, and given the FX of the time the first half an hour of the movie makes a game attempt to portray a crew operating in free fall in a spacecraft that actually looks somewhat plausible, given FTL. It's an odd contrast to the rest of the movie.
 * Though the film The Fifth Element has very few (and even less relevant) space aspects, it takes this trope to its logical conclusion: the luxury space cruise liner Fhloston Paradise is shaped like a steam paddle boat, and has a classical nautical steering wheel to make course corrections. The justification would be that it is a ship meant for recreation, and so letting the Rule of Cool determine its design (for the enjoyment of rich tourists) makes a bit more sense than it would for a vessel with a more mundane purpose.
 * The "borders" of the Solar System also have floating buoys in a single plane.

Literature

 * In Herman Melville's Moby Dick, Ahab says the line "...where in her murderous hold this frigate earth is ballasted with the bones of millions of the drowned..." comparing the planet itself to a ship sailing through the cosmos.
 * While the design of his spacecraft reflect a working knowledge of engineering, almost every book Robert A. Heinlein wrote that took place aboard a spaceship assumed nautical, particularly Naval, discipline and traditions, from Laz & Lor's stick-on Captain's insignia to Captain Hilda of the Gay Deceiver. This might have had as much to do with Heinlein's own Naval career as anything, although it has undoubtedly shaped the trope to some degree.
 * Referenced a bit more literally by the pseudo-Victorian colony the main characters of The Number of the Beast find on Mars in one universe: "space ships" are vaguely described to them as "sailing" from planet to planet.  (They later discover that the colony was actually an extensive "Potemkin Village" illusion hiding Barsoom from their sight; apparently those who crafted the illusion took the phrase "space ship" from them and interpreted it somewhat literally within a 19th-century context...)
 * The novel Berserker Fury is the World War II naval Battle of Midway In Space!. The AI robot ships are the Japanese and humanity is the Americans. Complete down to the planet named 50/50 (Midway), the "space carriers" Venture (USS Enterprise), Stinger (USS Hornet), and so on. They even broke the Berserker code, like the USA broke the Japanese Purple Code.
 * In the Halo books, Covenant command centers are located as deep in the ship structure as possible, and there are hints that the UNSC (United Nations Space Command, the interstellar human government) was consciously modeled after oceanic naval traditions. See the Halo entry in the "Video Games" folder, below.
 * The latest book, The Cole Protocol lampshades the foolishness of this placement, as well as the difference in philosophy when a raiding Covenant Elite speculates that humans have far more reckless courage than most other races of the galaxy.
 * The Honor Harrington novel series technology was set up explicitly so author David Weber could do Horatio Hornblower In Space, with formations of spacecraft blasting away broadsides at each other and even using "gravitational sails" to navigate hyperspace (hyperspace itself having "currents", "waves" and areas just too damn stormy...err, gravitationally random, to move through safely).
 * The overall plot was nice for most who knew their naval history, saying oh X is Y and so forth. Then Napoleon got nuked ...
 * Echoes of Honor is basically a retelling of CS Forester's Flying Colours—only much, much bigger. Instead of escaping with twenty prisoners in a dinky cutter like Hornblower, having destroyed three small rowboats sent to chase him, Honor escapes with half a million prisoners and an entire battlefleet, fighting major battles on the way.
 * An article describing various literary examples of "Hornblower in Space" (including Weber's) can be found here.
 * David Drake's RCN series is loosely based off the 18th century British navy, complete with spaceships that travel through hyperspace using sails. However, the sails are handled fairly realistically: stripping a ship's sails with a plasma cannon is a quick and easy way to keep it from escaping into hyperspace, the sails need to be furled and stowed before entering an atomsphere, and when deployed, interfere with the ships's realspace maneuvering and combat.
 * In the same way that Honor Harrington is Hornblower/Nelson IN SPACE, the RCN books are Patrick O'Brian IN SPACE, with Daniel O'Leary in the role of Jack Aubrey and Adele Mundy as Stephen Maturin (only with her being the ship's comms officer rather than its surgeon).
 * Drake's Reaches novels (Igniting the Reaches, Through the Breach, and Fireships) are Hakluyt's Voyages crossed with the adventures of Sir Francis Drake during the wars with Spain. It's 16th century exploration & piracy IN SPACE.
 * Used in Accelerando by Charles Stross to justify shooting digital communist lobsters into space. They want to return to the ocean, but as digital entities that's not possible. Putting them in a space ship's computer and launching it into space, however...
 * In Lando Calrissian and the Starcave of Thonboka, there is a species of giant rays that live in vacuum and consider it an ocean. The opening passage of the novel describes space as though it were an ocean.
 * Played straight in Vorpal Blade by John Ringo. Humanity's only spaceship is a converted nuclear submarine. He also speculates that there are "standing gravity waves" in interstellar space; the space equivalent of oceanic currents.
 * In Ender's Shadow, Bean arrives at Battle School and goes exploring. He remarks: "Most poles and ladderways would merely let you pass between floors -- no, they called them decks; this was the International Fleet and so everything pretended to be a ship."
 * Later on in Shadow Puppets Ender's father, after hearing a reference to a "dry dock", asks if there is also a "wet dock". Dimak's response is: "Nautical terminology dies hard."
 * Peter F. Hamilton's spaceships (especially in the Night's Dawn trilogy) are spherical, and for a reason: Adamist (that is, non-biotechnological) starships use a "ZTT drive" to jump across lightyears. The drive creates a wormhole that, like a black hole, has a spherical event horizon. Activating the drive while the ship is in non-spherical mode (that is, with sensors extended) will lead to everything beyond the event horizon being torn apart and compressed to fusion density. BOOM!
 * Edenist voidhawks, however, are far superior to Adamist ships in every way—including FTL travel—due to the fact that they are made of "bitek" (a biological material). Voidhawks are lenticular in shape rather than spherical. Blackhawks—bitek starships with Adamist commanders—on the other hand can be pretty much any shape.
 * Hamilton uses many Space Is an Ocean tropes, but in a manner that is far more 2001 than Star Wars.
 * In the Commonwealth Saga, a spaceship is built for exploration (because their wormhole technology doesn't reach far enough). . Somewhat justified because the first one was conceived by 21st century astronauts, and they acknowledge the fact that the design of both the ships stems from 20th and 21st century science fiction. In the Void Trilogy (set 1500 years later in the same verse), spaceships are comparable to nowadays ships, in terms of use, design, and diversity.
 * In "Night Train to Rigel" by Timothy Zahn, space is actually a railway system. Go figure.
 * Arthur C. Clarke's short story The Wind from the Sun. This is an interesting case because it manages to evoke the feel of ocean travel in space despite being a fairly realistic and hard work. It is a story about literal Space Sailing—using perfectly realistic solar sails, shown to behave the way one would expect given Real Life physics.
 * A note: despite 'Navigators', and a feudal setting, Dune space travel is not in the least an example of this trope - the Holtzmann effect, while never properly described, seems to work more like teleportation than anything else (huge distances are moved 'in the blink of an eye', actual 'sailing' is negligible on any scale, and space warfare non-existent apart form orbital skirmishes due to the Guild (who are neutral) monopoly on interstellar travel.
 * There are elements of this in the Legends of Dune prequel novels with disputed canonicity, which features plenty of space battles between the League Armada (later Army of Humanity) and the Thinking Machines. Unusual for this setting, though, the military ranks in use are all made up and, in fact, change throughout the trilogy. For example, the equivalent of a general would be a Primero (League Armada), a Bashar (Army of Humanity), and a Caid (post-Jihad). These fictional army ranks are also used by ship officers. Strangely, the novels have generals command both ground and space battles. One would think these would be two completely different types of combat, requiring different skillsets (you wouldn't put a naval admiral in charge of a ground battle or an army general in command of a fleet, would you?).
 * Harry Harrison makes an effort to avert this (to an extent) in his Starworld novel, although the novel only has one space battle. An engineer shows the protagonist (also an engineer) a clip of a space battle from an old sci-fi movie and asks him to point out everything in it that's wrong. The protagonist can't do it, as he knows absolutely nothing about space combat and space travel in general. Among others, the engineer points out that the ship in the movie maneuvered like an airplane (banking hard), was able to stop on a dime to hide behind a planetoid, was using energy weapons (while lasers and plasma weapons exist in this 'verse, they're only useful at relatively short ranges), and had windows. Actual space combat is explained as between ships many kilometers away from each other, and the only weapons being used are missiles (both conventional and nuclear), although they are often deployed as screens (an impromptu mine field) ahead of the fleet. The reason the engineer needs the protagonist's help is to help him iron out the last few kinks on the rebels' secret weapon - a mass driver using plain old metal balls as ammo. They also have short-range autocannons firing rocket-propelled bullets. The entire Curb Stomp Battle is ridiculously short. The Earth fleet gets crippled by the mass drivers' opening volley with the autocannons delivering the coup de grâce.
 * In Michael Flynn's Spiral Arm series, this is played with: the terms have clearly been lifted from ocean ships, but they mean very different things.

Live Action TV

 * Babylon 5 did dispense with the atmospheric flight analogies, but retained many of the naval ones. It is even mentioned on-screen in the movie "A Call To Arms" that the command decks of Earth ships are traditionally modeled on a submarine. Probably because submarine warfare is the closest analogue to space combat you are likely to find until it actually exists: the arena is 3D, visual targeting is useless and a small hole in the ship is a major problem rather than a minor inconvenience.
 * They did this specifically to avoid the cliche of a circular bridge with the captain in the center, popularized by Star Trek.
 * The Earth Alliance also has an interesting classification for ships, contrary to the modern one. All new post-Minbari War capital ships are classified as "destroyers", despite being the same, or even bigger, than the previous classes of ships. The two main classes of ships used during the war were the Hyperion-class heavy cruiser, much smaller and more maneuverable than the post-war Omega-class destroyer, and the Nova-class dreadnought, the Omega's predecessor. The later designs, the Warlock and the Victory class are both called destroyers. Not that using this terminology even makes sense in space.
 * Actually, they did have to rely on visual targeting during the Earth-Minbari War, as the Minbari Sharlin-class war cruisers were equipped with an advanced jamming system that prevented weapon locks.
 * The 2004 Battlestar Galactica avoided many of the traditional Space Navy trappings, to replace them with the trappings of a modern US Navy aircraft carrier. A case of Shown Their Work, there are many details lifted straight from modern naval procedure and culture. Your typical viewer likely has no idea why engineering types are called "snipes" for example.
 * Perhaps most notable the CIC (rather than the 'Bridge') is deep inside the ship, with no windows to the outside. Others include use of the terms CAG and CAP.
 * Lampshaded in Face of the Enemy. When stranded in a Raptor with a non-operational FTL, one of the crewmen in Felix's group begins praying to Poseidon. One of the Eights on board is puzzled since they're a long way from water. He replies that they're in a ship so it's close enough.
 * In a new Doctor Who episode, The Doctor realizes there is something wrong because of the lack of engine vibration—the assumption being that of course a spaceship would need engines constantly running to move through space.
 * Long-range spaceships are usually designed to accelerate for half of the distance (until the turnaround point) and then decelerate, so the engines are always in use. Now, Starship UK may not have had a set destination (and thus no turnaround point) but that's even less realistic: Picking a random vector and drifting is the worst possible way of approaching a star, let alone a habitable world.
 * Even if not needed for propulsion there would still be the need for power, lights, artificial gravity, etc.
 * Firefly made frequent use of the nautical metaphor, even though it was somewhat at odds with the style of the show as a "western in space". In particular, Mal will not stop calling the ship a "boat." "Wagon" wouldn't have had quite the same ring.
 * The Alliance cruisers in the series were designed to avoid this. The result is a ship consisting of four large vertical towers, with fighters and other craft launching upside-down off a flight deck at the "bottom" of the ship. It looked more like a mobile city than a ship. The smaller warships that appeared in Serenity resembled nautical vessels more, but that's likely because they're meant to operate in atmospheres as well as space.
 * From interviews and DVD commentaries, the feel of Serenity specifically was supposed to be submarine-oriented rather than ship-oriented, which does then make the nickname of 'boat' remind one more of "u-boat" (a German word for "submarine" even if in English it's used almost exclusively for German World War submarines) than surface ships and boats. This was deliberately designed to contrast with the Alliance 'floating cities' as a way of showing the concept of efficiency (submarine-like ships that don't waste any part of the structure) and decadent waste (alliance ships being designed to be impressive, but not efficient). Best highlighted in the episode "Bushwacked" when Kaylee displays a willingness to take on the Alliance single-handedly for daring to call Serenity a junker - Alliance ships are the junk vessels to her because of their (dangerous) lack of engineering logic.
 * Mystery Science Theater 3000 tended to vary in its depiction of space depending on which was funnier at the moment. In The Movie, the Satellite Of Love's controls were shown to be identical to a boat's helm, and Gypsy, piloting the satellite, was wearing a sailor's cap and singing a sea shanty.
 * In general, Space: Above and Beyond tended to have nautical metaphors for the larger craft and, like Battlestar Galactica, atmospheric flight metaphors for the one-person craft. The analogy seemed to be with an aircraft carrier.
 * Stargate SG-1 and Stargate Atlantis avert this trope in some ways, but follow it in others:
 * Since the Stargate program is run by the U.S. Air Force, it uses more Air Force than nautical analogies. (And with official Air Force technical advisors, they generally get the details right. One of the spacecraft in Stargate Atlantis was dubbed the "Puddle Jumper", an aircraft name (though it was called a Gate Ship by the original creators). Prototype USAF starships and fighters are dubbed "X-301" and similar, following Air Force practice for experimental aircraft.
 * On the other hand, the show also demonstrates how deeply entrenched this trope is, in that all major Earth starships are named like Navy ships, and in the fact that they're actually called "ships" as opposed to "aircraft" or "spacecraft."
 * In a possible reference to this trope, when Ba'al screws around with the timeline in Stargate: Continuum, the Navy runs the Stargate program in the alternate timeline instead of the Air Force. The original SG-1 are all slightly put off by this revelation. Which is a little strange, since this timeline's Earth does not have any starships.
 * In the British sci-fi series UFO it appears that Space Is The English Channel given the number of Battle of Britain tropes it draws upon: Moonbase is the beleaguered sector airfield, SID (Space Intruder Detector) the RDF radar post, and calmly-speaking young women (WAAF's) vector in SHADO Interceptors (Spitfires) against the anonymous alien invaders (German bombers). But given that the Moon takes 27.322 days to orbit the Earth, one wonders why the aliens don't just attack SHADO headquarters when the Moon is on the opposite side of the planet.
 * Carl Sagan famously said that "the surface of the Earth is the shore of the cosmic ocean," and devoted an entire episode of Cosmos to comparisons between sea travelers of old and space travelers of the modern day and future. But at no point does he attempt to claim any of the above ocean/space tropes are actually logical or viable, instead merely using the analogy to help others understand. He also had a habit of referring to all manner of spacecraft as "ships" - everything from small robotic probes to theoretical interstellar designs, though, again, this was just poetic license.
 * Inverted in SeaQuest DSV, whose premise was basically "The Ocean is Space".
 * The show pretty much ignores fluid dynamics whenever it's convenient and goes with the Water Is Air idea.
 * Enthusiastically embraced out of writer incompetence/ignorance in the classically ultra-bad series The Starlost, as seen in the design of the ARK model. There's no reason why the domes all needed to be only on one plane, "flat" relative to the rest of the ship; it would have been more practical (and realistic!) to have them radiating out from the central hull in all directions. The final design suggests that the modelmakers were unconsciously assuming gravity would always be "down", and that the domes all need to be pointing upward for a "sun" overhead -- and that the entire ARK would be floating on the surface of "space" like a raft.

Star Trek

 * Star Trek made as much of the nautical metaphor as it possibly could. The episode "Balance of Terror" hyperextended the metaphor by presenting a cloaked ship as analogous to a submarine.
 * That same episode egregiously featured Sonar in Space to the extent that the crew of the Enterprise had to be quiet while the Romulans were hunting them.
 * Of course, the whole point of the episode was because Gene Roddenberry had always had submarines in mind when developing this show and this was his chance to do a full blown submarine episode. It was apparently a conscious decision that every time science and submarine imagery conflicted, submarine imagery would win, which is why Spock gives the Enterprise away during "silent running".
 * Extending the metaphor that smaller craft are "boats", Picard's personal diplomatic craft in Star Trek: The Next Generation (shown on-screen only in The Movie Star Trek: Insurrection) is called a "yacht" (or a "gig") in the Technical Manual.
 * Played with in The Wrath of Khan, where the Enterprise beats Khan's ship by maneuvering in three dimensions. Spock specifically mentions this, saying Khan is used to "old wars" and thus doesn't think in three dimensions, only two.
 * Kirk is one to talk, though. He's still thinking of space as an ocean -- just one with submarines. Once he has snuck around Khan, instead of just reorienting the Enterprise and shooting forward, he "surfaces" back into his original plane to attack, sacrificing some of his surprise for no good reason!
 * More seriously, the nebula setting works into why things happen as they do: sensors don't work, so the only way for the ships to find each other is pretty much by looking out the windows, which changes which strategies are reasonable. The whole "Two dimensional thinking" thing probably only works because of the nebula: had Reliant's sensors been working, it wouldn't matter that Khan didn't think to look up or down: he could just ask the computer where the Enterprise was.
 * Also from The Wrath of Khan but in a different... dimension (sorry!), the design of the uniforms introduced in it are clearly influenced by old naval officer uniforms.
 * Star Trek had from the beginning drawn a historical line from the first marine ships of Terra's Age of Exploration to the ships and aircraft of the 20th century, from there to the first space flight vessels, and from there to the Federation spaceships. Just look at the opening credits of Star Trek: Enterprise! Also frequently mentioned was the fact that the name Enterprise had a long tradition, being carried by sailing ships, a U.S. aircraft carrier, a U.S. space shuttle, and finally by the first (fictional) starship of Earth. Picard even had paintings of naval vessels in his room and in Star Trek: First Contact there was a whole wall full of little golden facsimiles of ships and aircraft named Enterprise in the Captain's Ready Room.
 * A Star Trek novel described Starfleet regulations as being "copied from old US naval regs". While this book isn't canon, it does suggest that Starfleet was consciously modeled on an oceanic navy.
 * Apparently so, Gene Roddenberry had submarines in mind when he started making the original series, which is why he wanted the episode "Balance of Terror" to be made - it was all about the submarine imagery.
 * In the TNG episode "The Outrageous Okona" a small-time Han Solo clone cargo pilot tells Data "Life is like loading twice your cargo weight on your spacecraft. If it's parakeets and you keep half of them flying all the time it's alright." Funny. With a boat. But why would a space craft have a weight limit? It could possibly have an upper limit on mass, but parakeets have the same mass flying or landed.
 * A few productions of Gilbert and Sullivan 's H.M.S. Pinafore were set in the Star Trek universe.
 * Ironically, Star Trek creator Gene Roddenberry was an Air Force pilot himself.
 * The Star Trek: Deep Space Nine episode "Explorers" involves Captain Sisko playing Thor Heyerdahl in a replica of an ancient Bajoran ship powered by solar sails.
 * Extra points to this one in that the spaceship has actual rigging - rigging that has to be altered manually like a sailing ship. Apparently the Bajorans invented interstellar flight some time before things like hydraulics, computers or mechanisation...
 * Kirk, in the TOS episode "The Ultimate Computer": "'All I... ask is a tall ship and a star... to steer her by.' You... you could feel the wind at your back in those days. The sounds of the sea... beneath you, and even if you take away the wind and the water... it's still the same. The ship is yours. You can feel her. And the stars are still there, Bones."
 * Another maritime tradition that survives in Starfleet is the tradition of ship's captains performing wedding ceremonies. Both Kirk and Picard had this honor on the show, even saying the same words(presumably an official text for Starfleet captains): "Since the days of the first wooden vessels, all ship masters have had one happy privilege: that of uniting two people in the bonds of matrimony."
 * It was revealed in commentary for Star Trek: The Next Generation that the Enterprise-D was planned to carry whales and dolphins to help navigation as they are more experienced moving in 3-D space. Sci Fi Debris pointed out that bees would be just as effective.
 * Except that they're less inclined to help you than dolphins are.
 * In one of the novels (Dark Mirror by Diane Duane) the Enterprise-D does carry dolphins. Apparently, not only are they intelligent and capable of communicating with humans, they can sense dimensional distortions. Handy.
 * In fact, dolphins were canonically established to be part of the Enterprise-D's crew complement—Geordi takes someone to see them in "The Perfect Mate".
 * The new Star Trek movie certainly doesn't get rid of its Space Is an Ocean tradition, but it does have a bit more of a three-dimensional feel. If you look very closely at the beginning, for example, you see that that a ship is "upside down."
 * Later compounded by the spiraling camera angle at which the Enterprise approaches the Narada over.
 * It also employs the fact space is three dimensional when the Enterprise warps into the debris field from the destroyed fleet, and has to barrel roll as well as dive underneath large pieces to avoid them.
 * Star Trek: Nemesis was about the first Star Trek production that actually understood the concept of 3-D maneuvering (as well as a pitched space-battle in general). As one section of the Enterprise's shields started to fail under the tremendous firepower being traded, they would rotate the ship to present an undamaged side. As a result the two ships would alternate flying under and overtop each other.
 * In the Trek movie First Contact, this is averted in a rather neatly done scene in which Picard, Worf, and a supporting character must execute an EVA to dislodge some Borg who were trying to convert the navigational deflector into an FTL transmitter to call home for reinforcements. This device is located on the 'front' engineering section of of the Enterprise-E, usually facing 'forward'. However, for the trio outside the ship it's the 'top', and they approach it by walking along the 'bottom' of the saucer section, using magnetic boots, and the scene shows them walking upright and the Enterprise-E as being 'upside down' (to them). Later the navigational deflector on the 'front' is 'down' to Picard and Worf (and the viewers). For Star Trek is was an impressive bit of accuracy.
 * In Generations, Worf's promotion ceremony is held in a holodeck recreation of a 19th century British Naval vessel, complete with period uniforms and a plank.
 * Meanwhile, Undiscovered Country doesn't give such blatant overtones but while the Enterprise interior is being picked apart from top to bottom the atmosphere as a whole subtly gives the impression of an actual naval vessel in space. The ship's bell even rings in a few scenes.
 * TOS also used whistles before some broadcasts on the ships internal comms exactly the same as Navy ships do today. Originally, in pre-modern times, the whistle was used to call all hands to the deck to hear the days General Orders. Today, it's more to catch everyone's attention before the broadcast. Mostly it's just tradition. Tradition is EVERYTHING in the Navy. It even overrides common sense in most cases.
 * The fact that Dr. McCoy's nickname is Bones is also a reference to the sailing era-many a ship's surgeon was referred to as this.

Music

 * Not only is space an ocean in DAAS Kapital, but the spaceship of choice is a submarine!

Tabletop Games

 * The tabletop RPG GURPS Transhuman Space both uses and averts this trope. Set at the turn of the 23nd Century (2199-2205), in sci-fi universe that doesn't leave the Solar System, the United Kingdom's space forces are formed by the Royal Navy, while the Chinese are based on the Army Rocket Forces, and the American space force is an extension of the Air Force, who beat the Navy out in a bidding war. So the UK forces use naval metaphors, while the others don't.
 * The White Wolf role-playing game Mage: The Ascension also has an example of this, in that the Sons of Ether (techno-mages based around the ideals of pulp fiction sci-fi) actually have sailing spaceships which catch the "etheric" currents in space, known as Etherships. The fact that Ethernauts have a tendency to stand boldly on the deck of such ships dressed in nautical outfits that look like they've come right out of an Errol Flynn movie and fire lasers made to look like cannons is well in keeping with the 'stylish over "rational" science' Etherite mentality. It also irritates the hell out of their foes, as the Void Engineers are constrained by that silly 'no oxygen in space' rule.
 * In fact, the whole reason the Sons of Ether split with the Technocracy was because those stiffs decided to exclude Ether from the Scientific Paradigm they've been feeding the world - hence the name. And really, it's not "'stylish' over 'rational' science", it's just that Science(!) is too great to be confined by any one Paradigm, as "real" scientists (both Technocratic and Sleeper) are slowly discovering, as they venture into the realm of Quantum Physics...
 * Spelljammer - sailing ships in space!
 * Partially averted in BattleTech, while the ships are called ships, their decks are arranged in the manner of a tower or skyscraper, with the front being the top of the tower.
 * The implied setting for Fourth Edition Dungeons and Dragons includes the Astral Sea. Despite the Astral Sea being three-dimensional and possibly infinite, a "surface" exists that most creatures stay near out of instinct.
 * The Warhammer 40,000 spinoff game Battlefleet Gothic is a great example of this. The game and the ships in it joyfully embrace the coolest aspects of naval combat through history, with vast hypertech vessels using Napoleonic broadside-based tactics of lines and crossing the T, ancient Greek-style ramming and boarding actions, early 20th century torpedoes and torpedo boats... Eldar ships even have solar sails, need to be at the right angle to the sun to work most effectively, and sometimes tack.
 * Rogue Trader runs with this- there's more detail on life in a spaceship, and it's surprisingly similar to living on an Age of Sail vessel (only GRIMDARK, of course). It's also got that lovely submariny touch of Silent Running for stealth pruposes- in fact, this is stated to be the main way to disengage from a battle. Ships have a Fore, Aft, Left and Right side- no love for top and bottom...
 * Battle Space, the space-combat game based in the Battletech universe, avoids most of these aspects. While played on a 2D board, ships act in 3D space, there is no friction so all movement must be countered by spinning the ship around and applying thrust, some larger ships (jumpships/warships) have ambiguous hulls to hide the bridge (though, it should be pointed out that every captain would have intel on all non-top secret ships, so this would be moot), and fighters, dropships, and a few landing craft are the only things that can enter the atmosphere without being destroyed. There are still many that are unavoidable (space travel times, ship class names), but most of that is handwaved as otherwise it would be horrendously boring.
 * "Full Thrust" is a truly great tabletop wargame, with great background fluff, realistic (semi-optional) "vector movement" rules, and a variable unit system - the game system measurements come with a suggested (very reasonable) scale, but is in the end explicitly left up to the players to decide. In one game, 1 Movement Unit might be a single kilometre, while in another, it might be a whole AU or more. 1 point of Mass might be the suggested 100 tonnes and scale linearly, or it might be 10 and scale logarithmically.
 * Best of all, the turns do not alternate; the players write down their movement orders for the turn, fire ordnance based on anticipating the enemy's movement, move their ships, resolve ordnance fire and then take turns firing the main ship-to-ship weaponry - all in the same turn! Makes the game a lot more realistic, and more about actual tactics than quirks in the rules.
 * Starfire has fleets of starships, with size classes named things like "light cruiser", "battlecruiser", "superdreadnought", etc., who cruise under constant engine power and always follow their noses. The Terran Federation Navy is run by admirals, who give orders to starship captains. Messages sent between star systems have to be delivered by courier drone, or in person, since radio signals can't travel through a warp point. And, of course, the game is plated on a flat map, which in the first edition was even blue in color.
 * Traveller has 2D space.

Video Games

 * In the end of Sega Genesis game Ecco the Dolphin, Ecco.
 * The Escape Velocity series of shareware games use most of these aspects. Spaceships are ships, bridges are either at the front or on top, 2-d space, sound, only a few days to the next system, etc. However, until the player buys and "inertial damper," there is no friction in space (unless, oddly enough, a ship is disabled), which makes combat turn out like jousting.
 * The Free Space space sim games refer to spaceships in nautical terms. The militaries that use these ships are called are called navies, and use navy ship classifications and personnel ranking. Fighters are akin to World War II atmospheric fighters -- WorldWarII-style dogfights are actually mentioned on the box as a primary selling point. Free Space 2 even has a hidden pirate ship, the Volition Bravos, as an Easter Egg (it can be summoned using a cheat code).
 * Free Space's terminology is an interesting example. It turns out that "destroyers" are battleship/aircraft-carrier hybrids and the largets warships in the game, while "cruisers" are the smallest, cheapest warships. The second game, set 32 years after the first, introduces "corvettes" which are slightly smaller than destroyers. Fighter units are formed into "squads," with "wings" being tactical elements of up to four fighters. Since this occurs centuries in the future however, it's likely all these changes were intentional, especially since Volition hired an ex-Marine NCO as a military consultant.
 * Freelancer fits this trope to a tee. There is friction in space: you lose speed if you kill your engines, and your ship returns to normal speed once you stop hitting the afterburners. Spacecraft are called ships, and although civilian spacecraft are called fighters, transports, or even space trains, capital ships are known as cruisers, frigates and gunboats. You wander around a 2-D Space, capital ships have a bridge with a big window more often than not, the Sci-Fi Writers Have No Sense of Scale and somehow managed to create entire planets only a few times bigger than a tiny little outpost, and on top of that, planets and stations are like fixed islands, completely devoid of rotation and translation. However, the game is well done enough to actually make this weird form of outer space rather believable.
 * Much the same in EVE Online, with ship classes of Frigate, Cruiser, Battleship and so on, along with plenty of space friction. So much space friction in fact, that after much forum discussion it had been suggested that EVE space is more akin to Jello that water (Word of God says the programers cheated the space physics by using fluid dynamics formulas in the engine.)
 * The PC game Gratuitous Space Battles uses 2D space, friction in space and space fighters, Damaged ships even catch fire. Some mods have gone full circle, using the game to portray WW 2 naval battles.
 * Halo both uses and subverts this. The UNSC ships are fairly boxy, but still has the bridge on the outer portion with a big window. The Covenant ships however, have their bridges close to the centre of the ship; which also has a streamlined design. They do, however, avert 2-D Space; see that entry for details.
 * There is more detail about Halo in the literature section of this page.
 * The videogame Rogue Galaxy took this to the extreme end. All of the space ships are literal wooden ships, complete with masts, anchors and the like—except with rocket engines and forcefields built into them. They also have various interstellar lifeforms that look just like sea creatures.
 * The PC game Star General plays World War II IN SPACE for all it's worth, hardly surprising considering that the same developers brought us Panzer General and its successors. Not only do all the ships correspond almost exactly with their World War II namesakes, some of the factions seem to be Fantasy Counterpart Cultures for various combatants from World War II, including incredibly obvious Space Nazis.
 * Averted or played straight in the PC game Terminus, depending on the player's choice of "realism". The game features an actual sliding scale by which to set how realistically the ships move in space. If set to "Newtonian", there is no friction and thus constant motion does not require constant acceleration. Stopping requires using reverse thrust, and a ship's mass affects how well this works (trying to stop a cargo hauler full of ore will take minute at least). You can even overaccelerate and tear your ship apart, though they do give a max safe velocity. 2-D Space still applies, though.
 * Traveller Also has this heavily for the terran, er, imperial side. Naval style commands were for military ship crews, traders require ship's papers (an amusing bit of fluff has a crew wondering why it's called papers if it's all on computers), Captain and all the attendant ranks as well. Smaller ships would be called boats, and have gigs to pick up crew from larger ships.
 * Conquest: Frontier Wars has a Navy-life stucture with space battle ships and even a space aircraft carrier, other units do look more like airplanes.
 * The Space Is an Ocean idea is further emphasized by the Celareon ships looking like Space Whales.
 * The Star Ocean series uses this in the title. The space portions are also clearly based on Star Trek.
 * The first game even starts with a snippit of spoken dialogue taken directly from Star Trek—in English no less!
 * The Bioware RPG Mass Effect has this in spades, with nearly all of the terminology used by the Normandy crew (skipper, aye aye, aweigh, ashore...), the fact that the force it serves is the Alliance Navy, and the fact that a few other species' ships are given naval names as well (ex: the Quarian Flotilla). There are no particularly questionable uses of this trope, however.
 * The final mission of Mass Effect 2 shows the Normandy maneuvering through a debris field in a manner more suited to a stunt airplane than a ship. It seems that Mass Effect uses this trope for organizational and naming matters, but actual operations are a little better researched.
 * Jeff 'Joker' Moreau: It takes skill to make a ship bank in a vacuum. Don't think it doesn't.
 * The DS title Infinite Space refers to space as the "Sea of Stars" and ships generally follow the principles outlined in the intro. However, they do adopt wall formations instead of lines.
 * In the game Super Mario Galaxy, Bowser actually travels through outer space aboard what appears to be a flying sailing ship (which first appeared in the game Super Mario Bros 3).
 * Sword of the Stars uses the navy based naming conventions for ships, among some other standard features of this trope. In addition, the Whale people Liir take these descriptions further, describing their soldiers and explorers as "black swimmers", among other analogies.
 * Kid Icarus: Uprising takes this trope literally, as space is an actual ocean called the Galactic Sea where all the constellations are held in place.

Web Comics

 * The Sluggy Freelance takes this trope to extremes, with spaceships that have big honking sails on them. While solar sails are in fact a reasonably scientific idea, they probably wouldn't be slung on masts of craft which were basically spacefaring galleons, leaning instead towards thin sheets, many hundreds of kilometers across, designed to catch particles of the solar wind reflect photons. The characters are not in outer space in those ships, but rather in a kind of backwards universe where normal physics do not apply uniformly. It's referred to as "Timeless Space", and there is not only gravity and an atmosphere but also an ocean beneath them—but touching that ocean will cost a character all of their time and effectively kill them. Or so they think, at least.
 * The trope is referenced in this Irregular Webcomic strip, with the obligatory link to the TVTropes version of this page, where the NASA worker assures the (soon to be literally) Ascended Fanboy that Space Does Not Work That Way.
 * Pockett is built on this trope, complete with a sea-captain type space captain, tradional pirate syntax, and common navy crew protocol.
 * Used to great effect in Second Empire, in which a second-hand Dalek warship designed for slow bombing runs utterly curb stomps a fleet of attacking fighters and a much more heavily armed enemy cruiser merely by having the captain realize the immense possibilities the aversion of this trope affords.

Web Originals

 * The Endless Night is a podcast about Space Pirates, which is chock-full of nautical comparisons- from borrowing the names of famous sailors for main characters (such as Nemo, Odisseus, and Ishmael) to the titles of the episodes.
 * In Nexus Gate space is treated very much like an ocean. Why there are even space pirates who patrol the stars!
 * Mentioned by name in #2 of Cracked's 6 Sci-Fi Movie Conventions (That Need to Die).

Western Animation
"Zapp Brannigan: Comets - the icebergs of the sky!"
 * Futurama had an episode about a space cruise on a space ship called the Titanic. The episode goes pretty much as one would expect, with Zapp Brannigan (the captain of the Titanic) making as many comparisons between space and the ocean as possible.

Other
"The challenge was to create a degree of ambiguity between outer space and underwater with a fishlike craft at home in either environment."
 * Invoked in painting Aquaventura by Roger Dean.

Real Life

 * This tradition has gone on so long that assuming we do ever manage create routine space flight (which is unfortunately looking less likely) it is almost certain that this trope will be Defictionalized.
 * There are some fairly recent advances in space travel that look straight out of this trope.
 * Same principle, but it'd probably look more like a parachute.
 * It is a possibility that the Navy might take over space faring expeditions because they already function on a tradition of being out at sea for long stretches of time living off of the resources on the ship, whereas the Air Force eventually has to get their air crafts back on the ground to refuel. Though in the event of any such Space version of our regular Military Forces there might be room for Joint Military Task Forces or even have the Air Force adopt Naval Traditions to avoid having authority stripped from them in Outer Space.