The War Cog (for German and Dutch civs known as the Kogge) is a warship formerly unique to Friesland, but now available to all civs. It fires multiple arrows per shot (the extra arrows cause 1 damage each), and is the only warship in the game that can be upgraded at the Blacksmith. Friesland can upgrade the Kogge to the Holk.
Available to: All
Built at: Dock
Armor/Pierce Armor: 0/5
Special: +13 vs. ships and lancers, +7 vs. buildings, +4 vs. rams. 8 armor vs. anti-ship units. Range and attack can be upgraded at the Blacksmith.
Upgrades to: Holk (Friesland only)
Upgrade Century: 15th
Kogge (Austria, Bavaria, Flanders, Friesland, Guelders, Helvetia, Saxony)
Civs and the War Cog
Friesland: costs -20%
Genoa: 165 wood, 135 florins; takes longer to construct
War Cogs make excellent warships, but have even better usage as a support vessel, though Galleys are cheaper and attack quicker. War Cogs excel at more things, so it's definitely worth it to save the extra resources for War Cogs. Galleys, however, still have their uses in the early stage of the game.
A cog is a type of ship that first appeared in the 10th century, and was widely used from around the 12th century on. Cogs were generally built of oak, which was an abundant timber in the Baltic region of Prussia. This vessel was fitted with a single mast and a square-rigged single sail. Even though this type of rigging prohibited sailing into the wind, it could be handled by a smaller crew, which reduced operational costs. These vessels were mostly associated with seagoing trade in medieval Europe, especially the Hanseatic League, particularly in the Baltic Sea region.
In times of military struggles and to defend the loaded goods from pirate attacks, the cog was equipped with soldiers, but also canons.