Carriers

Carriers are a support unit with no attack or defense strength of their own. They do two jobs.

First, they move your jets to a battle: one carrier carries up to 100 jets. Without enough carriers, your jets cannot reach the enemy.

Second, they carry goods for trade between empires.

Carriers are very cheap to keep. A common way to earn gold is to set your industry to build carriers and then sell them. This can earn more than producing gold directly.