Ocean

“Beyond the horizon lies nothing but water, wind, and the unknown. Only the bold dare cross.”

Ocean represents the deep, open waters far from any coastline. These vast expanses produce no yields and cannot be improved, but they must be crossed to reach distant continents and explore the full extent of the map. Early naval vessels cannot venture into ocean tiles – only with the discovery of Astronomy can civilisations navigate the open sea.

Yields

Movement

Restrictions

• Galleys cannot enter ocean tiles. Early naval units are restricted to coastal waters. Only ships unlocked after researching Astronomy can navigate ocean tiles.
• Ocean tiles cannot be improved.
• Ocean tiles cannot be worked by cities.

Strategy

Ocean tiles are obstacles in the early game and highways in the mid-to-late game. Before Astronomy, ocean hexes are impassable barriers that separate continents and isolate civilisations from one another. This isolation can be a blessing – protecting you from early aggression – or a curse, if it limits your expansion options.

Once Astronomy is researched, ocean tiles become navigable, opening up an entirely new strategic dimension. The first civilisation to achieve ocean navigation gains an enormous advantage: the ability to discover new continents, establish colonies, and launch naval invasions against unprepared opponents. Prioritise Astronomy if you suspect there are landmasses across the ocean worth reaching.

In terms of naval combat, ocean tiles offer no defensive advantage. Fleets caught in open water have no terrain bonuses to rely on, making naval engagements in ocean hexes a straightforward contest of fleet strength. If your navy is weaker, stay near your coastal cities where city defences can support your ships.

Historical Background

For most of human history, the open ocean was a terrifying and impassable void. Ancient Mediterranean sailors hugged the coastline, navigating by landmarks and rarely venturing out of sight of land. The Polynesian peoples were a remarkable exception, crossing vast stretches of the Pacific Ocean using sophisticated navigation techniques based on star positions, ocean currents, and the flight patterns of birds.

The European Age of Exploration in the 15th and 16th centuries was made possible by advances in navigation technology – the magnetic compass, the astrolabe, and improved ship designs like the caravel. When Vasco da Gama rounded the Cape of Good Hope in 1498 and Columbus crossed the Atlantic in 1492, they connected civilisations that had developed in complete isolation for millennia, with consequences that reshaped the entire world.