The height difference between the source and the mouth of the Amazon River is not large. In addition, the Amazon River is located in the rainy equatorial region. The riverbed is deep, wide and flat, and the flow rate is very slow, which is suitable for shipping. The Port of Manaus is an important port on the Amazon River. The Amazon River has very favorable shipping conditions. It not only has abundant water, wide and deep rivers, but also has a slow gradient. There are no dangerous shoals or waterfalls on the main river sections, and it does not freeze all year round. The main stream and major tributaries can be directly navigable, thus forming a huge and convenient water shipping network. A 3,000-ton ocean-going ship can go up the main stream to Iquitos, 3,680 km away, and a 10,000-ton giant ship can reach Manaus in the middle reaches. The navigation conditions of each tributary are also quite favorable. The navigable distance of some major tributaries exceeds 1,000 km (for example, the navigable distance of the Purus River is 2,853 km, and the navigable distance of the Madeira River is 1,090 km). The total length of navigable rivers in the entire water system is over 25,000 km.