Traditional fishing boat were used for war and trade. Some ancient vessels were propelled by either oars or sail, depending on the speed and direction of the wind (see trireme and bireme). The Chinese were using sails around 3000 BC, of a type that can still be seen on traditional fishing boats sailing off the coast of Vietnam in Ha Long Bay. A jangada is an elegant planked fishing boat used in northern Brazil. It has been claimed the jangada dates back to ancient Greek time. It uses a triangular (lateen) sail, which allows it to sail against the wind. A felucca is
Cataracts of the Nile Cataracts of the Nile The Cataracts of the Nile are shallow lengths (or white water rapids) of the Nile River, between Aswan and Khartoum, where the surface of the water is broken by many small boulders and stones jutting out of the river bed, as well as many rocky islets. In some places, these stretches are punctuated by whitewater, while at others the water flow is smoother, but still shallow. Counted going upstream (from north to south): The word cataract is a Greek word καταρρέω ("to flow down") although the original Greek term was Κατάδουποι(, οἱ - only masculine plural