At Porto Alegre, near the Atlantic coast, the Jacuí transforms into a shallow estuary, known as the Guaíba River, and flows into the Patos Lagoon. Boats can travel up the river as far as Cachoeira do Sul.
In the vicinity of Porto Alegre, on the Atlantic coast, the Jacuí River becomes a shallow inlet known as the Guaíba River, emptying into the Patos Lagoon. Vessels can reach as far upstream as Cachoeira do Sul via this waterway.