River boats from Manaus, Brazil

In the Amazon, there are not many roads.

The rivers are like long water roads. Boats carry people, food and supplies from town to town.

In the state of Amazonas, the main way to reach towns in the interior is by river. A geographer at the State University of Amazonas writes that, where there are no roads or highways, the rivers carry people, goods and ideas.

Brazil's waterway transport agency, ANTAQ, said in 2021 that river travel is the most important way to move people and goods in the Amazon region, linking its many communities. It estimated about 13.6 million passenger trips a year there, including short river crossings.

ANTAQ's 2021 regulatory impact report calls passenger river navigation the most important means of transport for people and goods in the Amazon region, connecting communities and centers of production, trade and consumption along its waterways, with an estimated demand of 13.6 million passengers a year including crossings. It notes that road, rail and air infrastructure has low coverage, leaving waterways as the social and economic link.

Kristian Oliveira de Queiroz (GEOUSP, 2019) adds that the main access to the interior cities of Amazonas is the river network, that the Solimões is fully navigable upstream only from Manaus to Coari, while the Amazon is navigable all the way from Manaus to Belém, and that Amazonas has only 30 passenger terminals across its 62 municipalities, with no organized port in any Solimões municipality. An ANTAQ study he quotes (2013) found most Amazon lines served by outdated vessels, often wooden or decades old, with recurring problems of comfort, hygiene and safety that it put down to the need to charge low fares.

One big river boat studied in Manaus had three decks.

On the decks, there are hooks for hammocks. Passengers who bring a hammock can tie it up and rest as the boat moves along.

The traditional Amazon passenger boat is called a recreio, or navio motor. It carries passengers and cargo together. One big wooden boat studied by researchers in Manaus, the Almir Araújo, had three decks above the hold, 12 cabins with air conditioning, a kitchen, a bar and toilets.

It had 180 hooks, enough to tie up 90 hammocks, and carried up to 180 passengers. The researchers noted that the boat had no seats, so a passenger without their own hammock would be uncomfortable. On its route to Barreirinha, about 330 kilometers away in a straight line, it took about 24 hours going downstream and 31 hours coming back against the current.

Queiroz classifies Solimões passenger craft into the N/M (navio-motor) or recreio, the traditional mixed passenger-and-cargo boat; the expresso or Ajato launch, which prioritizes passengers and speed; and the ferry-boat (F/B), which performs like an N/M but, he notes, does not let passengers use hammocks, only cabins.

Gaspar et al. (Rosa dos Ventos, 2021) profiled the Almir Araújo: 220 tonnes, 33.98 m long, a 420 HP engine, three decks plus the hold, 12 air-conditioned cabins, 80 life jackets and 10 life rafts, capacity for 180 passengers and 180 hooks for 90 hammocks. A Manaus-Barreirinha round trip (about 330 km in a straight line) used about 1,600 liters of diesel at an average of 25 km/h: 24 hours downstream and 31 upstream. The authors list the lack of seats, or of a passenger's own hammock, among its limitations.

Some boat trips from Manaus take a whole day.

Some take about four days! Fast boats called expressos can make some trips in hours instead of days.

From the Porto Roadway, boats leave every day for towns up the Solimões, as far as Tabatinga on the border with Colombia and Peru. Others go down the Amazon into the state of Pará, a trip that takes about four days on average, according to the 2021 study.

Faster boats called expressos, such as those of the Ajato company, mostly carry passengers. In 2016, an Ajato launch took about 12 hours to reach Tefé, 631 kilometers up the Solimões, and launches took about 36 hours to reach Tabatinga. Expressos carry only small amounts of cargo.

Gaspar et al. counted, from the Porto Roadway (data updated February 2021), 18 navios-motores, one barco-motor, 15 ferry-boats and one balsa serving Coari, Tefé, Fonte Boa, Jutaí and Tabatinga on the Solimões, with daily departures toward Tabatinga, and Amazon-river boats crossing into Pará on trips of about four days on average.

Queiroz's 2016 survey of the Ajato group lists the Ajato 2000 (72 passengers) to Tefé, 631 km, in 12 hours, three departures a week, for R$230, and launches to Tabatinga in 36 hours for R$570. He reports that Ajato began as a service around Manaus in 1993 and started Solimões routes in January 2000. For scale, he cites Bates's account of 1855 steamers taking 18 days to travel 1,800 km upstream from the Rio Negro to Nauta in Peru.

The rivers around Manaus go up and down during the year.

Some years, the water gets very high. Other years, it gets very low, and big boats have a hard time moving.

Two rivers meet just east of Manaus. The Rio Negro is dark like tea, colored by decayed leaves and plants. The Solimões is coffee-colored, full of mud from the Andes. They flow side by side for several kilometers before mixing.

River levels shape boat travel. In 2012, water at Manaus rose higher than in at least a century. In October 2023, during a drought, the Rio Negro at Manaus fell below its old record low. Brazil's Geological Service measured its lowest point that year, 12.70 meters, on 26 October. NASA, citing news reports, said low rivers slowed boats carrying goods. In October 2024, NASA reported record low rivers in the Amazon basin again.

NASA's Earth Observatory (2012) describes the confluence east of Manaus: the cooler, denser, faster Solimões, carrying Andean sediment, and the warmer, slower Negro, stained by decayed plant matter, run side by side for several kilometers before mixing into the lower Amazon. That June, levels at Manaus were the highest in at least a century.

In October 2023 the Rio Negro at the Port of Manaus fell to 15.14 m on 3 October and 13.49 m on 17 October, a record at that date (NASA, from Port of Manaus data); ANA had reported on 16 October that it had passed the old minimums of 13.63 m (2010) and 13.64 m (1963). It kept falling to 12.70 m on 26 October, 93 cm below the 2010 minimum, in Brazil's Geological Service (SGB) station table. NASA, citing news outlets, reported slowed commercial navigation and drinking-water disruption for hundreds of communities. NASA reported more record lows across the basin in October 2024, including the Solimões near Tabatinga at 254 cm below its gauge's zero, and cited reports of communities struggling to get supplies; its 2024 article gives no Manaus level, and no official page giving the 2024 level at Manaus could be opened for this topic.