The term 'Ancient Vessel' refers to two different types of ships from antiquity. The first is the ARGO, a four-letter ship that was used by the legendary Greek hero Jason and the Argonauts in their quest for the Golden Fleece. The second is the BIREME, a six-letter ship that was used by the ancient Greeks and Romans in naval warfare. Both vessels were powered by oars and sails and were used extensively in the Mediterranean region.