"Svart ships are made using unprecedented technology. Svarts do not use sails, so they build special machines that move the oars. Such rowing engines allow their ships to ignore the changeable winds, and slowly and steadily approach the target in any weather.
The main force of the Svart fleet is two-towered oared frigates. These vessels feature a reinforced shell and low profile, which makes them a difficult target for enemy gunners."
(from "Chronicles of New Worlds" written by Master Vardies Teleran)