Sea Forces

A Sea Base is the foundation of naval power.

• Cost: $2,500
• Strength: 1,000, Armor: 5, Upkeep: $100
• Placement: on owned land sector adjacent to water. Built by Construction Truck.
• Research: Sea track, position 3.

A Sea Base:

• Produces all sea units. Newly built ships spawn on a nearby water sector (within a short BFS through water from the base).
• Heals sea units in adjacent water that didn't move/fight that cycle (Land Bases do the same for land units sitting on the base's sector).
• Anchors your naval supply line. A sea unit's upkeep is measured in water hops to the nearest friendly Sea Base — ships moored next to one of your Sea Bases pay baseline upkeep, while a sub stranded an ocean away pays up to 3× as much. Pushing Sea Bases forward onto captured coasts is how you keep an expeditionary fleet affordable.

Note that a Sea Base lives on a land sector even though it produces sea units. The land sector is the building; the water around it is where the fleet lives.

Transport

• Cost: $3,500
• Move: 7, Attack: 50, Range: 17, Armor: 4, Upkeep: $30
• Can carry one land unit across water; transport penalty of 2 movement reduction when loaded.
• Research: Sea track, position 6.

Transports are how your land forces cross oceans. Load a Tank or some Infantry at a coastal sector, move to the destination coast, unload. Transports can defend themselves in combat but aren't offensive ships.

Warship

• Cost: $10,000
• Move: 6, Attack: 120, Range: 15, Armor: 3, Upkeep: $80
• Fire range: 3 sectors, fire power: 15.
• Research: Sea track, position 9.

The coastal bombardment unit. A Warship in water near a coastal sector can shell land targets within its fire range. Warships also engage other naval units directly — they're the fighting ship of the line.

Typical Warship play: park a Warship off an enemy coast, let it soften defenses (Refineries, Turrets, coastal bases) each cycle before a land invasion. Warships stack well with land pushes — coastal softening makes land combat easier.

Aircraft Carrier

• Cost: $7,500
• Move: 7, Attack: 90, Range: 17, Armor: 4, Upkeep: $60
• Air capacity: 9 Jets. Functions as a mobile Air Base at sea.
• Research: Sea track, position 12.

Carriers project air power anywhere in the world. Jets stationed on a Carrier fly from the Carrier's current sector instead of a fixed Air Base. This means you can strike deep into coastlines that don't have a nearby friendly Air Base.

Carriers are produced next to an Air Base so Jets can be loaded onto them (Jet build is adjacent to a Carrier parked near a coastal Air Base).

Missile Frigate

• Cost: $7,500
• Move: 7, Attack: 90, Range: 17, Armor: 4, Upkeep: $60
• Air capacity: 9 Missiles.
• Research: Sea track, position 15.

A mobile missile launcher — the Frigate holds Missiles and launches them at land targets. Same basic mechanics as the Carrier but for Missiles instead of Jets.

Submarine

• Cost: $9,000
• Move: 5, Attack: 100, Range: 13, Armor: 3, Upkeep: $70
• Hidden — invisible to enemies.
• Research: Sea track, position 21.

The stealth naval unit. Subs path through water like other ships, but they don't appear on enemy maps. They strike from ambush, taking first-shot advantage against surface ships they encounter.

Detection mechanics (all automatic, not probabilistic):

• Enemy submarines within 2 water hops detect a sub via sonar.
• Spy Planes scanning over water reveal any hidden subs inside the scan radius.
• Defense Turrets within 1 hop of the sub's water sector expose it to that country.
• Firing a torpedo also auto-reveals the attacking sub to anyone in the target sector.

Once detected, the sub is visible to that country but isn't killed by the detection itself — they still have to destroy it in combat.

Sea Mine Layer

• Cost: $2,500
• Move: 6, Attack: 40, Range: 15, Armor: 2, Upkeep: $25
• Deploys and sweeps Sea Mines. See Structures.
• Research: Sea track, position 18.

Lays invisible mines on water sectors. Any enemy ship entering a mined sector takes armor-scaled damage and stops moving for that cycle — the attack order resumes next cycle. The mine is consumed on trigger. Sea Mine Layers can also sweep (remove) mines safely. See Structures for the full damage table.

Sea combat resolves during Phase 3 (Sea Attacks). A typical cycle:

• Ships move along their queued paths through water sectors.
• Warships within fire range of enemy coastal targets bombard them, dealing damage to units, bases, and structures.
• When ships enter sectors with enemy naval units, combat resolves.
• Transports carrying land units continue to their destination.
• Submarines attack surface ships they encounter.

Damage follows the same Combat rules — armor, Health, Skill, randomness. Naval battles happen on water sectors and use the general damage math.

To move a land unit across water:

1. Position a Transport somewhere in water (it doesn't have to be touching the cargo's sector — the cargo will pathfind to it).
2. Queue a Board Transport order on your land unit, targeting the Transport's water sector. The land unit marches along the shortest path to reach the Transport that cycle.
3. Give the Transport an attack path toward the destination coast. With cargo aboard, it spends an extra 2 movement per cycle on top of normal terrain costs.
4. Queue Disembark to drop the cargo onto a land sector adjacent to the Transport's sector or anywhere along its queued path.

Each step is a separate order, so a full cross-ocean invasion typically takes several cycles. Plan it with the disembark sector in mind — the cargo can step off anywhere along the Transport's path, not just at the final stop.

Sea units path through water only. Water sectors connect to other water sectors via the same adjacency graph used by land. Bridge segments (even though over water) are land-traversable but not sea-traversable — sea units route around them.

Coastlines matter because:

• Warships fire at coastal land targets within their fire range.
• Transports can only load/unload on adjacent coastal sectors.
• Submarines can ambush surface ships around coastal chokepoints.

Sea units run their own supply network: a ship's upkeep distance is measured in water hops to the nearest friendly Sea Base, not against your Land Bases. A Warship sitting next to a Sea Base pays baseline upkeep; the same Warship 20+ hops out across open water pays up to 3× as much. Push Sea Bases forward onto captured coasts to project sustained naval power affordably — a fleet far from any Sea Base bleeds the treasury fast.

A sea unit completely disconnected from any of your Sea Bases (no water path back, e.g. trapped in an enclosed sea your Sea Bases can't reach) is treated as fully out of supply and pays the maximum penalty.

• Transport invasions work best when softened first. Land a Warship nearby a cycle or two ahead and soften the beaches. Otherwise your Transports arrive into intact defenses.
• Carriers for power projection. A Carrier loaded with Jets in a theater far from any Air Base is sometimes your only option for air coverage.
• Frigates are single-purpose. They're missile launchers — once loaded, they're expensive one-trick ponies. Treat them like a deployable silo.
• Submarines hunt in groups. A single Sub is easy to lose to a Spy Plane. Two together counter enemy subs and still pose a surface threat.
• Mine your coastlines. A ring of Sea Mines around important Sea Bases denies cheap raids.
• Coordinate with treaty partners at opposite coasts. They won't share vision, but they can agree to attack what you both can see, funneling enemy fleets into coordinated pressure.