Ship spawn refers to the computer-controlled brigand and barbarian ships that will try to engage player ships in a sea battle. The might ring color that a player ship can spawn up to is indicated by route difficulty, but also depends on the result of the previous battles the player ship has fought, and the crewing levels of the player ship. In some cases, larger ships will spawn if the player ship is near or at maximum crew capacity.
The likelihood of spawning an enemy ship is increasingly reduced with better performance at the navigation puzzle, when the player ship is configured for trade, evading, attacking flotillas or sea monsters. A voyage configured for a pillage or a greeter pillage, on the other hand, will increase the likelihood of enemy ships spawning as the navigator scores higher.