Imagine a world where the vast interiors of continents are forbidden, where humanity’s cradle is not the fertile river valley but the windswept coast. In Civilization 6, this hypothetical scenario—where all civilizations are restricted to settling only on coastal tiles—represents one of the most profound strategic shifts possible. It’s a challenge that fundamentally rewrites the game’s core assumptions, transforming the familiar race for land into a desperate scramble for control of the seas. Land-based empires become an impossibility, naval power becomes the ultimate arbiter of destiny, and the rhythm of expansion, warfare, and trade is dictated by the tides. This guide delves into the strategic depths of this unique scenario, analyzing the new hierarchies of power and the tactical adjustments required to not just survive, but to dominate a world tethered to the ocean.
The Great Maritime Shift: Core Gameplay Changes
Forcing all settlements to the coast fundamentally alters the strategic landscape. The player community widely agrees that this single rule change has a cascading effect on nearly every aspect of gameplay, from the value of tiles to the very definition of a “good” start.
A New Economic Reality
Analysis on forums shows that the most immediate change is economic. Early-game production, traditionally sourced from hills, forests, and mines, becomes scarce. Coastal water tiles, with their base yield of one food and one gold, are notoriously poor for production. This creates an early-game production deficit that can feel crippling. Civilizations must pivot their economic priorities entirely.
- Gold Becomes Paramount: With production hampered, gold emerges as the most critical resource. A strong treasury allows a player to purchase builders, settlers, and even military units, compensating for the lack of production capacity. Trade routes, especially sea-based ones, are no longer just a source of income but a vital lifeline.
- The Harbor as the Economic Heart: The Harbor district is elevated from a strong choice to an absolute necessity. It is the engine of the coastal empire, providing not only gold and a trade route but also the crucial buildings that make sea tiles viable. The Lighthouse adds food, the Shipyard adds production based on adjacency, and the Seaport provides a final boost to yields. Many professional gamers suggest that the first district built in every single city, without exception, should be the Harbor.
- Rethinking Tile Yields: The traditional hierarchy of tile yields is inverted. A plains-hill tile, normally a top-tier production source, is worthless if it’s three tiles inland. Conversely, a seemingly barren stretch of coast gains immense value. Access to sea resources like Fish, Crabs, and Whales becomes a primary factor in settlement decisions, as these are the only way to make water tiles productive in the early game. The “God of the Sea” pantheon, granting +1 production from Fishing Boats, is almost universally considered the best choice in this scenario.
Redefined Expansion and City Placement
The mad dash to claim territory in the center of a landmass is replaced by a strategic dance along the world’s coastlines. Settlers, once free to roam, are now leashed to the sea.
- Choke Points and Control: Control of the sea is control of movement. Straits, peninsulas, and island chains become the new strategic choke points. A well-placed city with a strong navy can blockade entire sections of the map, cutting off rivals from expansion and trade.
- The “Coastal Reach” Calculation: When settling, the primary consideration is no longer just the immediate resources but the “coastal reach.” A city’s three-tile radius must encompass as many sea resources and potential Harbor locations as possible. A popular strategy is to settle in a way that maximizes the number of workable coastal tiles, even if it means sacrificing access to a few land-based luxury or strategic resources.
- Housing and Growth: Without access to rivers and lakes, fresh water becomes a major constraint on growth. While coastal cities receive a base of +3 housing (compared to +2 for inland cities without fresh water), this is quickly outstripped by population growth. This makes buildings like the Granary and improvements that provide housing, like Indonesia’s Kampongs, exceptionally valuable. The Aqueduct district, while still useful, is less of a priority as it provides less housing from saltwater.
Masters of the Ocean: Top-Tier Coastal Civilizations
Not all civilizations are created equal when the world is flooded. The established tier lists are thrown overboard, and a new naval hierarchy emerges. Analysis of community discussions consistently places a select few civilizations at the pinnacle of coastal dominance.
S-Tier: The Unquestioned Rulers
Portugal (João III): Often cited as “broken” or “god-tier” in any water-heavy map, Portugal’s advantages become overwhelming in a coast-only world. Their entire design is a masterclass in maritime economics.
* Casa da Índia: This leader ability grants a free trade route whenever Portugal meets a new civilization and makes all international trade routes yield 50% more. In a world where every city is coastal and trade is paramount, this ability generates a staggering amount of gold.
* Nau and Feitoria: The Nau, a unique Caravel replacement, comes with a free promotion and, more importantly, two build charges to construct Feitorias. A Feitoria is a unique improvement that can be built in a foreign coastal city, granting Portugal a copy of every luxury resource the city owns and providing bonus gold and production to Portuguese trade routes passing through. This allows Portugal to effectively “claim” the resources of other civilizations without going to war.
* Navigation School: This unique building, replacing the University, provides bonus production for naval units in its city and bonus science for every two coastal or lake tiles within the city’s borders. It directly addresses the production and science challenges of a coastal start.
Indonesia (Gitarja): If Portugal is the master of coastal economics, Indonesia is the master of coastal versatility. Gitarja’s toolkit is perfectly suited for a water world.
* Exalted Goddess of the Three Worlds: This ability is a powerhouse. City centers gain +2 Faith for being adjacent to a coast or lake tile. This early faith generation allows Indonesia to secure a pantheon quickly and can fuel a religious game or be used to purchase naval units with the Grand Master’s Chapel.
* Jong: The Jong is arguably one of the best unique naval units. It replaces the Frigate but is unlocked earlier, requires no Niter, and has a powerful ability that grants it +5 combat strength and +1 movement if it is in a formation. A fleet of Jongs is a terrifying sight in the mid-game.
* Kampong: This is the cornerstone of Indonesia’s coastal strength. The Kampong is a unique improvement built on coastal water tiles that provides +1 production, +1 housing, and +1 food for every adjacent Fishing Boat. It single-handedly solves the core problems of coastal cities: low food, low production, and limited housing. A city filled with Kampongs becomes a growth and production powerhouse.
A-Tier: The Formidable Contenders
England (Victoria or Eleanor): England has always been a naval power, and in this scenario, its strengths are amplified.
* Royal Navy Dockyard: This unique Harbor replacement is built in half the time, provides +1 movement for all naval units built in its city, and grants a free naval unit on a different continent. This allows England to rapidly build and project a powerful navy across the globe.
* Sea Dog: The Sea Dog, a unique Privateer replacement, has the incredible ability to capture defeated enemy naval units. This can snowball an English navy from a small fleet into an unstoppable armada, turning enemy losses into English gains.
Norway (Harald Hardrada): The quintessential coastal raider, Norway thrives in the early chaos of a water world.
* Thunderbolt of the North: This ability allows all Norwegian naval melee units to perform coastal raids, pillaging enemy tiles for gold, science, and culture. This “coastal raiding economy” can sustain Norway through the difficult early game and cripple its opponents.
* Viking Longship: An early Galley replacement, the Longship can heal in neutral territory and is cheaper to produce, allowing Norway to field a large, aggressive navy from the very beginning of the game.
The Harbor is King: District and City Management
In a coast-only game, the Harbor is not just a district; it is the central pillar of your civilization’s success. Every decision about city planning must revolve around maximizing the effectiveness of your Harbors.
The Unrivaled Power of the Shipyard
While the Lighthouse’s food and the Seaport’s yields are important, the Shipyard is the building that truly transforms coastal cities. The Shipyard provides +1 production for every coastal or lake tile in the city. More importantly, it grants production equal to the gold adjacency bonus of its Harbor district. This is a game-changing mechanic. A popular strategy is to carefully plan district placement to maximize this bonus. A Harbor adjacent to the city center and two other districts can have a +4 gold adjacency, which the Shipyard then converts into +4 production. This single building can provide more production than several mines, directly solving the production deficit of coastal cities.
Strategic District Adjacency
With land at a premium, district placement becomes a complex puzzle.
* The Commercial Hub/Harbor Combo: Many professional gamers suggest building a Commercial Hub adjacent to your Harbor. This creates a “trade nexus” that maximizes gold income and generates Great Merchant points, further boosting your economy.
* Coastal Adjacency Bonuses: Certain districts gain bonuses from being on the coast. Campuses get a bonus from reefs, and Theater Squares get a bonus from wonders, many of which are coastal. Japan, for example, excels at this, with its “Meiji Restoration” ability granting standard adjacency bonuses for all districts, making coastal district clusters incredibly powerful.
Naval Doctrine and Dominance: Warfare in a Coastal World
When every city is a port, every war is a naval war. Land armies become secondary, used primarily for the final capture of a city after it has been bombarded into submission by a fleet.
The Combined Arms Approach
Analysis on forums shows that the most effective naval strategy is a combined arms approach.
* Ranged Naval Units (Quadriremes, Frigates, Battleships): These are the workhorses of your navy. They are used to bombard coastal cities, whittle down enemy fleets from a distance, and control key sea lanes.
* Melee Naval Units (Galleys, Caravels, Ironclads): These units act as a screen for your ranged ships, engage enemy melee units, and are essential for capturing coastal cities.
* Raiding Units (Privateers, Submarines): These units are perfect for disrupting enemy trade. A few well-placed Privateers can plunder trade routes, starving an enemy empire of the gold it needs to function.
The Importance of Great Admirals
Great Admirals are even more critical in a coastal world. Their retirement bonuses can provide powerful unique units or massive boosts to your entire navy. The Mausoleum at Halicarnassus, which grants an extra charge to all Great Admirals, becomes a top-tier wonder for any civilization aiming for naval dominance.
Wonders of the Waves: Prioritizing World Wonders
The wonder race is also re-contextualized. Many S-tier wonders on land maps become difficult or impossible to build, while previously niche coastal wonders become essential.
- Mausoleum at Halicarnassus: As mentioned, the extra Great Person charges make this a must-have for any naval power. It also provides bonus science and culture for every Great Person expended.
- The Great Lighthouse: An early wonder that provides +1 movement to all naval units. This seemingly small bonus is incredibly powerful, allowing your fleets to project power faster and your trade routes to reach farther.
- Venetian Arsenal: This industrial-era wonder grants a free copy of every naval unit you train. It effectively doubles your naval production, allowing you to build an overwhelming force. Securing this wonder is often a game-winning move.
- The Colossus: Another early wonder, the Colossus provides an extra trade route and a free Trader unit, giving an early and significant boost to the all-important gold economy.
Surviving the Tides: Early Game Survival and Expansion
The first 50 turns are the most challenging. A poor start can leave you hopelessly behind.
- Settle Smart: Your starting location is critical. Look for a coast with at least 2-3 sea resources (Fish, Crabs, Whales). Access to a luxury resource is also a high priority to manage amenities.
- Tech and Civic Path: The path is clear: rush Sailing, then Celestial Navigation to unlock Harbors and the Great Lighthouse. For civics, prioritize Foreign Trade to unlock trade routes.
- Pantheon Choice: “God of the Sea” is the optimal choice 99% of the time. The +1 production from Fishing Boats is essential to get your economy off the ground.
- First Build: Your first build should almost always be a scout to explore the coastline and meet other civilizations, followed by a builder to improve your sea resources. Then, focus on getting a settler out to claim a second valuable coastal location.
Conclusion
The coast-only challenge in Civilization 6 is more than just a quirky ruleset; it is a complete strategic overhaul. It forces players to abandon land-based instincts and embrace a new maritime mindset. Success is no longer measured in the breadth of one’s territory but in the strength of one’s fleet and the depth of one’s treasury. The Harbor becomes the heart of the empire, gold becomes the lifeblood, and control of the sea becomes the ultimate expression of power. By understanding the fundamental shifts in economy, expansion, and warfare, and by choosing a civilization built to rule the waves, a player can transform this challenging constraint into a thrilling new way to experience the grand strategy of Civilization 6.