Sea mines detonate on attacking ships before the battle starts, piercing their armor. Detonated mines are spent and each detonation costs half of the sea mines, so repair them to re-arm. Mine Countermeasures Ships clear mines before they explode. Each level lays an additional layer of mines.

Mine fields detonate on attacking troops before the battle starts, piercing their armor. Detonated mines are spent and each detonation costs half of the mine field, so repair it to re-arm. Mine Sweepers clear mines before they explode. Each level lays an additional layer of mines.

Bunkers shelter 100 defending troops per level, halving the damage they take. A damaged bunker shelters fewer troops. Attacking Artillery bombard bunkers before the battle, ignoring their armor.

Anti aircraft guns defend this region against air, sea and ground attacks. Against aircraft they fire flak before the battle starts, which ignores the armor of bombers and escorts, while agile fighters take only half of it. Each level adds more guns, increasing both defence and durability.