Lake Nahuel Huapi, inside the national park of the same name at 765 metres above sea level, offers freshwater diving with visibility up to 22 metres and seabeds that combine rocky walls, caves and subaquatic forests. Water temperature hovers around 10°C year-round. Because of the altitude, each recorded depth requires a 10% safety margin above standard sea-level decompression tables, so altitude dive planning is mandatory.
The most popular sites are Isla de las Gallinas (2 km offshore, with a 3-metre Neptune sculpture and a submerged cable-car cable) and the San Miguel shipwreck at Isla Victoria (14-16 m; interior access restricted to advanced divers). The Moreno sector has walls reaching 50 m, suitable only for two-star certified divers or above. The lake is home to rainbow and brown trout, freshwater clams and river crabs.
Best season is November to April when water is slightly warmer. The certified operator is Ardilla Buceo (Ruta 77 km 21, Lago Moreno; +54 2944-247000), a National Diving School endorsed by the Argentine Naval Prefecture. Oceanica Buceo also offers guided dives and courses in the area.
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