Your excursion is a minuscule subset of the Amazon River, the world’s largest by volume. The Amazonas (Portuguese) headwaters are in the Andes in central Peru. Over 1,000 tributaries join the easterly, 4,000 mile flow across northern Brazil. When the Amazon arrives in the Atlantic Ocean – 900 miles from Manaus – the 300 mile wide mouth empties up to 500 billion cubic feet of fresh water a day.