Geography and context
Lake Lácar is a glacial lake in Neuquén Province, Argentina, located within Lanín National Park. According to Wikipedia, it covers approximately 49 km², stretches around 25 km long by 3 km wide, and sits at 625 metres above sea level. Its waters drain westward into the Pacific Ocean via the Hua-Hum River — an unusual feature for Andean-Patagonian lakes, which typically drain toward the Atlantic.
San Martín de los Andes sits on the lake’s eastern shore in the Vega de Maipú valley and serves as the main gateway to Lanín National Park. Lanín covers 412,013 hectares across Patagonian Forest and Patagonian Steppe ecoregions, administered by Argentina’s National Parks Administration (APN) at Perito Moreno 1006, San Martín de los Andes (Tel. +54 2972-427233).
What you’ll see
Lácar is a high-altitude dive site. At 625 metres above sea level, atmospheric pressure is lower than at sea level, which modifies nitrogen absorption rates and requires specific altitude decompression planning — standard sea-level tables do not apply directly.
The lake’s glacial-origin floor combines rock, fine sediment and remarkable clarity for a mountain lake. The park supports abundant fish fauna including trout and salmon, both naturally occurring and maintained through local fish hatcheries. Freshwater clams and river crabs are also present.
Diving is explicitly listed as a permitted activity in Nahuel Huapi National Park (adjacent to the south), and the same normative framework applies within Lanín under APN coordination.
When to go
Recommended season runs December to March, when water temperatures are highest and weather conditions are more stable for water activities. In winter the lake is accessible but conditions are more demanding, and exposure protection must be planned accordingly.
How to get there
San Martín de los Andes is reached from Neuquén capital via National Route 40 and Provincial Route 234, approximately 420 km. The nearest airport is Chapelco Airport (SMZ), 24 km from town, with regular flights from Buenos Aires. Long-distance bus connections run from Neuquén and Bariloche.
Protected areas and regulations
Lake Lácar lies within Lanín National Park (IUCN Category II). Water activities require coordination with the APN. The Argentine Naval Prefecture (Prefectura Naval Argentina) regulates all commercial diving and boating: operators and vessels must hold valid permits.
The western section of the southern shore is designated a strict reserve to protect the Andean-Patagonian and Valdivian rainforest ecosystems.
Park entry fees apply at control points. Current rates at argentina.gob.ar/parquesnacionales/lanin.
Technical tips
Diving at Lácar is in its early stages — there is no established operator running regular scheduled dives on the lake, so consult operators in San Martín de los Andes or Bariloche before planning your trip. At 629 metres above sea level, altitude diving rules apply: dive computers must be set to altitude mode and no-decompression limits are shorter than at sea level. Entry to Lanín National Park requires an APN fee, payable at park checkpoints — check current rates at argentina.gob.ar/parquesnacionales/lanin. Lake access from San Martín is straightforward, but shore entry points are not mapped for diving; arrive prepared to scout the shoreline as an unexplored destination. A 7 mm semi-dry is the minimum for summer; a drysuit is recommended from autumn through spring.
Sources
- Wikipedia ES — Lago Lácar (geography, dimensions, watershed)
- Wikipedia ES — Parque Nacional Lanín (fauna, regulations, area)
- argentina.gob.ar — Lanín National Park (APN contact, visit planning)
- argentina.gob.ar — Nahuel Huapi National Park (permitted water activities — comparable regulatory reference)
- APN — Resolution 706/2023 — Fishing regulations PN Lanín (fishing season Lake Lácar: 01/11–31/05)