The boat wheels and heads up the Rio Negro, named after its black, naturally acidic waters. The two passengers on this trip stretch out in pool chairs on the upper deck, which doubles as the roof. The sun pours down and up, reflecting off the river. Sunscreen is a survival item. Leaving the city behind, the boat chugs past beaches of glittering white sand.
Egrets perch on the gray skeleton of an abandoned fishing shack.
Rising above the forest canopy on the left bank is the Ariau Amazon Tower, the Ritz of jungle resorts. Actor Kevin Costner and German Chancellor Helmut Kohl stayed here, but most tourists prefer a place with fewer frills. Nearly four hours after setting out, the boat veers left into the Rio Acajatuba. Around another bend, almost hidden in the forest, is the thatch-roofed Acajatuba Jungle Lodge. The boat ties up at a catwalk that leads up to an open-air lobby, where manager Gustavo Santos waits with a complimentary glass of jenipapo liqueur, made from a local fruit.