Circuito Paulista de Maratonas Aquáticas 2026 — Natividade da Serra

On the morning of April 26th, the quiet streets of Natividade da Serra undergo a transformation as local residents gather near the banks of the Paraibuna Reservoir. For the community, this day marks the return of the Maratona Aquática Igor de Souza, an event that brings a concentrated influx of swimmers to this municipality of fewer than 7,000 inhabitants. The organizers, led by Igor de Souza, rely on the vast, calm expanse of the dam, which serves as the primary aquatic stage for the event. Locals who once relied on the river's flow now see these waters become a controlled track for marathon swimmers, with the transition from the town's mountainous 720-meter elevation down to the reservoir level defining the logistical flow of the race day.

The reservoir environment

Swimming in the Paraibuna reservoir differs significantly from coastal circuits found further east in São Paulo. The water here is stable, lacking the salt and currents that characterize the Atlantic, but the sheer scale of the basin requires swimmers to manage their own pacing across distances that lack traditional shoreline landmarks. Athletes often arrive early to navigate the access points around the Bairro Alto district, where the infrastructure remains geared toward rural accessibility rather than mass sporting events. Registration and technical meetings are handled directly by the organizing team, who provide specific instructions regarding the buoy line placement within the reservoir's wide, flooded valleys. Because the reservoir covers a significant portion of the Paraibuna/Paraitinga region, water temperatures remain relatively consistent with the surrounding valley climate during late April, typically requiring no thermal gear for the majority of participants. The competition format follows the established standards of the Circuito Paulista, maintaining a rigorous check-in process to ensure safety across the designated courses, while the surrounding hills of the Paraíba Paulista valley provide a natural windbreak that keeps the surface conditions predictable for the duration of the event.