RTS games where the navy actually matters
Most real-time strategy games treat the sea as a place tanks cannot go. A few make it a front. The games that get naval warfare right, from Forged Alliance to Sea Power, and how Steel Tide's sea works — shipyards, sonar, submarines and transports that carry weight.
Water is the hardest thing to put in a real-time strategy game. Land units cannot enter it, so it splits the map; ships cannot leave it, so they need their own factory, their own economy and their own reasons to exist; and if the navy cannot hurt the land, nobody builds one. Most RTS games solve this by making the sea small, or decorative, or absent.
A few games make the sea a front. Here are the ones we think get it right, and then an honest account of how Steel Tide's navy works, because a game with nine ships, two aircraft that hunt them, and a map where two thirds of the ore is out in the water has opinions on the subject.
The ones that made the sea a front
Supreme Commander: Forged Alliance (2007) is the model: sea is one of its four theatres alongside land, air and information warfare, and on its bigger maps the fleet is the economy's shield and the enemy's front door. The community's Forged Alliance Forever client has kept it playable online since 2011 and was still growing in 2024.
Beyond All Reason carries that forward on the open-source Recoil engine — land, sea and air across three factions, free, with hundred-player games on maps where whoever holds the water holds the metal.
Command & Conquer: Red Alert 3 (2008) is the boldest naval design a mainstream RTS ever shipped. Its designers said so out loud: naval warfare was to be "another front", many units were made amphibious, trading effectiveness for flexibility, whole bases could be built on water, every multiplayer map had significant water in it, and a player who ignored the ocean was "forfeiting a significant part of their potential economy". Its predecessor Red Alert 2 had the dreadnoughts, carriers and submarines that made people care in the first place.
The Age of Empires games have had docks, transports, fishing and sea trade since 1997, and on a water map an Age of Empires IV or Age of Mythology: Retold match is won on the coast as often as on land.
Wargame: Red Dragon (Eugen Systems, 2014) added naval forces to a series that had not had them, and is the honest counter-example: IGN called its naval simulation "deeply silly". Putting ships in a game is easy. Making them matter is not.
The ones that are only the sea
Sea Power: Naval Combat in the Missile Age (Triassic Games, early access since November 2024) is NATO against the Warsaw Pact at sea, from the lead designer of Cold Waters, with a dynamic campaign added in 2026 and a full release planned for late in the year. If you want to know what a modern naval engagement actually looks like — sensors first, missiles second, ships last — this is the one.
Ultimate Admiral: Dreadnoughts (Game-Labs, 1.0 in January 2023, still updated in 2026) lets you design the warships before you fight with them, from the coal-fired 1890s to radar-directed gunnery.
And if a navy in space counts, Homeworld 3 and Sins of a Solar Empire II are fleets all the way down.
How Steel Tide's sea works
Ships come from the shore. A Naval Yard has to be placed on the shoreline, and a headquarters supports three production buildings in any mix, so a navy costs you a factory or an airbase. It upgrades once for the advanced warships and again, with a radar station, for the two Level-3 boats.
Submarines are a hard counter. A submerged boat is invisible to anything without sonar and untouchable by anything without torpedoes. The Orca Destroyer is the only surface ship that carries sonar; the Cormorant is the only aircraft, with a dipping sonar and torpedoes that have to be dropped into water. Without one of them, the Barracuda sinks your fleet from under it, and once it has a radar and a reactor behind it, it fabricates a warhead of its own and launches it from beneath the surface.
The sea shoots the land, and the land shoots back. The Sovereign Battleship bombards coast and sea from extreme range. The Kraken fires cruise missiles at land targets from underwater at twelve tiles while seeing only six, so it needs a spotter, and a Missile Interrupter on the target can shoot its missiles down. The Albatross answers from the air with sea-skimming anti-ship missiles; the Aegis Frigate is the fleet's air-defence screen against it. Every one of those matchups is a row in the counter table: naval guns, anti-ship missiles and torpedoes are weapon classes, ship and submarine are armour classes, and a weapon that cannot target a domain does no damage at all.
Transports carry weight. A Landing Craft holds four points of cargo — four light vehicles, two medium, or one Mammoth — and its ramp only reaches the tile beside its hull, so it has to nose up to a beach. The Moray carries the same hold underwater, invisible to anyone without sonar, which is how a squad of engineers ends up on the ore behind an enemy base.
The maps ask for all of it. Archipelago is islands and straits. Leviathan Strait is isolated homelands and resource islets. Saltbone Reach seats six on the rim of a drowned mountain range with two thirds of the ore out in the water, thirty-odd islets, four islands worth a second base and no bridge anywhere — a homeland there feeds one base and never an army, and whoever will not put engineers on boats loses to whoever will. Four Climes has an inland sea and a central island with no ore on it. Ironmouth has a river you can ford above the rapids and sail below them.
What it does not do yet
The AI does not use transports. On an island map it fights with navy and aircraft, which caps an AI seat at the ore of its own landmass, and it is why the naval maps are at their best with humans in the seats. There are no hovercraft and no amphibious tanks: if you want armour on the far shore, something has to carry it, and something else may be waiting underwater when it does.
That is the point. Try Saltbone Reach with a friend and see who puts the engineers on the boat first.