In Imperator there is only one type of naval unit, the Trireme. The strengths and weaknesses of these ships can then be modified by things like Trade Goods, Military Traditions, Admirals, Inventions, and more.
There are unit abilities for ships at sea:
- Ramming Tactics: Navy Offensive Damage +10% Navy Defense Damage -10%
- Boarding Tactics: Navy Offense Damage -10% Navy Defense Damage +10%
- Raid Port: Steals a number of pops from an adjacent port and turns them into Slaves in your capital (at a cost of 1 Aggressive Expansion).