Considerably larger than the more common trireme, the Bireme are the premiere warships of the Inner Sea. With two decks of oarsmen, these vessels are designed to tower over their smaller cousins, and also over the sea walls of many cities and fortresses, giving the warriors aboard the ability to fire down on fortified positions, and also to disembark onto elevated fortifications. Suited to the calm waters of the Inner Sea, the Bireme cuts through the water, riding high, and with a full compliment of oarsmen it can move at speed that belies its immense size, though its hull is still low enough to restrict its choice of safe harbour. The bierme's lack of agility, however, means that as a cargo ship or for general passage it is far outstripped by smaller vessels.


Biremes and their ilk outstrip the maritime vessels of nearly all other races of Allornus, save for the kardesian longships. Built by goblyns as the heart of the Great Fleet of Ashiva Mas-Kujabi, the bireme was based on drawings of old marinervessels, modified slightly to suit the calmer, more buoyant waters of the Inner Sea. Like the smaller, trireme the design of the bireme can be modified to maximize accommodation, propulsion, weight and waterline, centre of gravity and stability, or hull strength depending on the desired purpose of the vessel.

The arrangement and number of oarsmen is the first deciding factor in the size of the ship. For a ship to travel at high speeds would requires a high-mounted oar-gearing; it is this arrangement of the oars which is unique and highly effective for the bireme. The ports house the oarsmen with a minimal waste of space. There are three files of oarsmen on each side, tightly but workably packed by placing each man outboard of, and in height overlapping, the one below. The lower oarsmen act as fulcrums to the oars that allowed them to move. The centre of gravity of the ship is low because of the overlapping formation of the files that allow the ports to remain closer to the ships walls. A lower centre of gravity provides adequate stability.

The bireme is constructed to maximize all traits of the ship to the point where if any changes were made the design would be compromised. Speed is maximized to the point where any less weight would result in considerable loss to the ship's integrity. The centre of gravity is placed at the lowest possible position where the lower oarsmen sit, just above the waterline, making it almost impossible to roll the vessel. Biremes require a great deal of upkeep in order to stay afloat, in terms of the regular replacement of ropes, sails, rudders, oars and masts. They also become waterlogged long before their structures begin to deteriorate, but they are far too large to drag ashore without special equipment. For this reason most biremes are abandoned after ten to fifteen years of service. Often, to recoup some of the vessel's value, they are traded to boat people, who beach them on reefs to serve as permanent moorings in bad weather.