create a penteconters an ancient Greek galley in use since the archaic period rowed by fifty oarsmen, arranged in a row of twenty-five on each side of the ship. A midship mast with sail could also propel the ship under favourable wind. Penteconters were long and sharp-keeled ships, hence described as long vessels (νῆες μακραί, nḗes makraí ). They typically lacked a full deck, and thus were also called unfenced vessels (ἄφρακτοι νῆες, áphraktoi nḗes). Very Rough seas big waves