The Rio Igaraçu is a distributary of the Parnaíba River in northern Piauí state, flowing from its origin on the Parnaíba southwest of the city of Parnaíba to its mouth on the Atlantic Ocean near the city of Luís Correia. The river spans approximately 11.5 miles and forms part of the intricate channel network of the Parnaíba Delta, one of the largest river deltas on the South American coast. Portions of the river fall within an Environmental Protection Area administered by ICMBio, Brazil's federal conservation agency.

The primary way to access the river is by boat, with tours and excursions typically departing from Parnaíba or nearby coastal towns. Parnaíba itself is reachable by bus or plane. The river's channels wind through extensive mangrove forests, and some guided boat tours offer opportunities for kayaking or paddleboarding within the waterways. Infrastructure along the river is limited, which is worth factoring into trip planning. Flow monitoring stations are located at Porto De Vera Cruz and Capitânia.

The delta environment along the Rio Igaraçu is characterized by mangrove ecosystems, mobile dunes, and natural pools. The area known as Canto do Vieira, situated along the river's banks between Parnaíba and Luís Correia, is accessible by canoe, motorized boat, or by 4x4 vehicle via Praia da Pedra do Sal. The combination of mangroves, shifting dunes, and tidal channels gives the paddling experience a distinctly coastal, estuarine character rather than a freshwater river feel.

Given the tropical location at approximately 2°52′S latitude, temperatures are warm year-round. Booking guided boat tours in advance is advisable during peak tourist season to secure availability. Paddlers should wear quick-drying footwear suitable for boat travel and potential light walking in mangrove terrain.