Roman Triremes image - Kings and Conquerors: The Hellenistic Era mod for Rise of Nations: Thrones and Patriots

Naval combat is being reworked with new ship classes, new ways to destroy ships, and potentially some new uses for ships. Also, as you can see in this picture, the ship sizes will be more realistic.

Shown here is the Roman version of the trireme, which comes under the 'medium ship' class. And yes, this means that there are also light and heavy ship classes. The Romans can build ships from all three of these classes.