The standard war vessel of this period in the empire is the Dromon, a long and low ship of simple design. The Dromon is outfitted with, lateen sails and a single row of oars, typical 25 on each side. There is sometimes a single deck to protect the rowing crews from arrow or catapult fire. The front of the Dromon is equipped with a ram and some vessels have small ballistas or catapults mounted on the bow. The typical Dromon is 135 feet long and between 20 and 30 feet wide and crewed by 60 to 70 sailor soldiers.
Image Attribution: By Spiridon Ion Cepleanu (Own work) [CC BY-SA 4.0 (http://creativecommons.org/licenses/by-sa/4.0)%5D, via Wikimedia Commons