In the stone ages primitive boats developed to permit navigation of rivers and for fishing in rivers and off the coast. It has been argued that boats suitable for a significant sea crossing were necessary for people to reach Australia an estimated 40,000-45,000 years ago. With the development of civilization, bigger vessels were developed both for trade and war. In the Mediterranean, galleys were developed about 3000 BC. Dugouts are the oldest boats archaeologists have found, dating back about 8,000 years to the Neolithic Stone Age. This is probably because they are made of massive pieces of wood, which tend to preserve better than, e.g., bark canoes. "Primitive Man" by Louis Figuier, 1871. This image has been color-enhanced.