Slow boats down the Rio Madeira to Manaus (R$290 hammock, double cabin with fan/air-con R$790/1020, 2½ days) leave Tuesday, Wednesday and Saturday at 2pm from Porto Cai n’Água at the end of Rua 13 de Maio. You'll need your own hammock, and meals are available for purchase. Buy tickets from one of the brokers at the port, including Agência Monte Sinai and Agência Moreira. You can claim a spot and sleep on board two to three days before departure.
The bus station is 2km east of the center.
Eucatur runs daily buses to Rio Branco (R$115, nine to ten hours, four daily) and Cuiabá (R$220 to R$369; 26 hours, eight daily), with connections to Brasília and beyond.
Viação Rondônia runs seven daily buses to Rio Branco (R$115, nine to ten hours).
Collective taxis serve Guajará-Mirim (per person R$120, four hours). The price is based on a minimum of four passengers, so you may have to wait for the car to fill up.