Which river has the longest navigable section?

The Amazon is often cited as the river with the longest navigable section because large stretches of its channel and tributaries can be travelled by river transport. Depending on water level and how navigation is defined, boats can travel very far inland from the Atlantic coast. This immense navigable network is one reason the river has been so important for trade and movement in the Amazon Basin. River navigation on the Amazon is seasonal in many areas, with high water opening routes that are less accessible in the dry season. Its scale makes it one of the most important inland transport systems on Earth.