ACNRP Rio de la Plata 2026

La course

Crossing the Río de la Plata is not merely a swim; it is a rite of passage into the elite circle of global marathon swimming. As the widest river in the world, this legendary 40km stretch connecting Argentina and Uruguay serves as a profound test of endurance, mental fortitude, and respect for the raw power of nature. Steeped in history, the crossing gained international recognition as early as 1923, when the pioneering Lilian Harrison defied the societal norms of her era to become the first person to conquer these waters. Today, the Asociación Cruce a Nado Río de la Plata (ACNRP) preserves this centennial tradition, ensuring that every crossing is managed with the precision of a major maritime expedition.

What makes this challenge truly unique is the 'mystique' of the river itself. The water, rich with sediments carried from the Andes, is famously opaque and brown, creating an immersive experience where the swimmer must rely entirely on the rhythmic sound of the water against their body and an internal sense of connection. It is a journey of transformation—a sentiment echoed by veterans of the sport who view the river as a living, breathing entity. Whether you are an experienced marathon swimmer looking to complete the prestigious South American Triple Crown or an adventurer seeking the ultimate personal challenge, this event offers an unparalleled encounter with one of South America’s most iconic natural landmarks.

Beyond the physical test, the event serves as a vibrant point of convergence for the international open water community. Buenos Aires provides a sophisticated, culturally rich backdrop for the lead-up to the event, blending European-style architecture with the passionate, welcoming spirit of Argentina. After your training sessions or the race itself, there is no better way to celebrate your achievement than to {{link:experiences|explore the vibrant local culture}}, from world-class tango halls to the historic neighborhoods of San Telmo. For those traveling with a support crew or family, the city offers an endless array of attractions, ensuring that your journey to the start line is just as memorable as the finish. If you are ready to test your limits in one of the most storied bodies of water on the planet, we invite you to {{link:accommodations|find where to stay}} and begin preparing for an experience that will stay with you long after you reach the Uruguayan shore.