The Deseado Ría — a tidal estuary at the mouth of the Deseado River declared a Provincial Natural Reserve — is one of the most biodiverse marine ecosystems in southern Patagonia. Tidal currents concentrate zooplankton and microorganisms, sustaining a visible food chain: coastal fish, octopus, Commerson’s dolphins (Cephalorhynchus commersonii), cormorants and sea lions inhabit the estuary year-round. Visibility varies with tide and current conditions.
Diving takes place at sheltered sites away from the main tidal channels, generally on rocky reefs and cobble bottoms. This is not a mass-market destination — the offer is small but authentic, with outings that combine snorkelling, kayaking and scuba depending on daily conditions. The site requires solid experience in current management and mandatory tide-based planning.
The local operator is Ría Extrema (Puerto Deseado, +54 297 487-1065 / +54 297 15 625-8180), which offers nautical excursions and guided dives inside the reserve. Best season is October to March, when Commerson’s dolphins and cormorants are most active.
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