Most seats on the busses need to be reserved, so don't count on turning up and moving on like you might in Colombia or Venezuela . Just turn up at the quay for schedules of the boats. Three to five days sleeping in hammocks on the deck is fun, but the rice and fish can get monotonous, so bring a bag of goodies to cheer you up. Some of the boats have bars, and quite a party can be had if you meet up with a good crowd. If time is limited and your budget extends to it , you may consider covering the large distances by air.
Many international airlines fly to Brazil.
The Brazilian Air Pass is an economical way to travel within the country . The Mercosur Air Pass is an economical way to travel between Argentina , Brazil, Chile , Paraguay and Uruguay . It is priced by air miles travelled and is available to anyone arriving from outside South America. Minimum of 2 countries and maximum of 4. Minimum of 2 stop-overs and maximum of 8.