The Rio Acari is a river in the state of Amazonas, Brazil, flowing through a region that includes the 896,411-hectare Acari Sustainable Development Reserve. This designation suggests the area is protected, focusing on sustainable use and conservation, which likely influences the overall character of the paddling environment. The river's coordinates are approximately 5°16′56′′S. For paddlers, specific access points and planning tools for the Rio Acari can be found through the PaddleWays platform, which provides maps and information on water conditions and private or public land boundaries to aid in trip preparation. The river flows through the heart of the Amazon, indicating a remote and natural setting dominated by rainforest. Paddlers should expect a wilderness experience with significant biodiversity. The presence of a large sustainable development reserve implies that the river's aesthetic is one of pristine tropical nature, with water quality likely being good due to the protected status. Paddlers must be prepared for a self-sufficient expedition in a remote area with limited facilities. Regulations would be those typical for a protected Brazilian reserve, requiring permits and adherence to conservation guidelines. There is no information indicating that paddling is prohibited.