In Amazônia, rivers have been the main highways for centuries, and the Amazon itself is navigable to ocean-going ships as far west as Iquitos in Peru, nearly 3000km upstream from Belém.
In all the large riverside cities of the Amazon – notably Belém, Manaus and Santarém – there are hidroviárias, ferry terminals for waterborne bus services. Amazon river travel is slow and can be tough going, but it’s a fascinating experience. On bigger boats, there are a number of classes; in general, it’s better to avoid cabine, where you swelter in a cabin, and choose primeiro (first class) instead, sleeping in a hammock on deck. Segundo (second class) is usually hammock space in the lower deck or engine room. Wooden boats are much more comfortable than metal, but usually slower. Take plenty of provisions, and expect to practise your Portuguese.
The range of boat transport in the Amazon runs from luxury tourist boats and large three-level riverboats to smaller one- or two-level boats (the latter normally confining their routes to main tributaries and local runs) and covered launches operated by tour companies. The most popular route is the Belém–Manaus trip, which takes four to six days.