Saco do Mendanha is a substantial open-water crossing within the Lagoa dos Patos estuarine system in Rio Grande do Sul. The primary paddling experience is a long, exposed crossing of approximately 10 kilometers, made from the area near Ponta do Retiro towards the communities of Passinho and Capivaras. This crossing represents a significant open-water challenge. The water body is subject to strong winds and opposing currents, which can severely increase the difficulty and risk for paddlers, particularly later in the day. The area features high dunes and white sand beaches along its shores, with views of the city of Rio Grande in the distance. For paddlers attempting the crossing, the communities of Capivaras and Passinho serve as potential take-out or rest points, where basic supplies might be obtained from local vendors. The overall character is that of a demanding coastal lagoon crossing requiring careful planning. The safest conditions are typically found in the early morning when the lagoon is calmer, as wind and chop tend to increase later in the day. Beyond the Saco do Mendanha itself, paddlers in this region may continue towards points like Ponta Rasa and Ilha da Sarangonha, though venturing to unknown islands late in the day with fatigue, wind, and contrary currents is a poor decision. The area is also adjacent to major shipping channels, as a separate 13-kilometer crossing towards Ilha da Torotama involves traversing a navigation channel, indicating significant boat traffic in the broader lagoon system.