Cabo Polonio tide times

Cabo Polonio occupies a rocky headland on the southern edge of Rocha Department, jutting into the South Atlantic at the end of a dune system that runs 20 kilometres along the barrier beach from Route 10. There is no electricity grid here, no permanent paved road, and — for most of the year — no more than a hundred people. The community that does live here has chosen to, and the infrastructure reflects that: gas lamps, solar panels, water tanks, and a rhythm set by wind and tide rather than power schedules.

The primary landmark is the lighthouse, built in 1881, standing 27 metres above the headland. It remains operational and marks the turn of the coast for southbound traffic on the Río de la Plata approaches. Below the lighthouse and across the rocks to the north and south, a year-round colony of South American sea lions (Otaria flavescens) hauls out — between 1,000 and 2,000 animals depending on the season, with the colony at its largest during the austral summer breeding period (November through January). They are loud, they smell, and they are completely indifferent to observers on the path above. The bulls, which can reach 300 kilograms, occupy the prime haul-out rocks and move only when they choose to.

The dune system behind the beach is one of the largest active dune formations on the Uruguayan coast, rising to 40 metres in places. The dunes are not stable — they migrate slowly inland under the prevailing south and southwest winds, burying vegetation as they advance. Walking through them at any point in the day, you are likely to be the only person in view in any direction. In January, that same landscape will have 3,000 visitors camped along the beach access points, with 4WD trucks making runs every hour from the Route 10 trailhead.

The trucks — seasonal, unscheduled, operating on demand when enough people have gathered — are the standard transport option for those who don't want to walk the dunes. The walk takes 45 minutes to an hour through soft sand; the truck takes 15 minutes and charges a few hundred Uruguayan pesos per person. In summer, they run continuously. Outside the peak season (roughly December through February), service becomes unreliable and the walk is the only option.

The beach north of the headland faces northeast and takes the full fetch of South Atlantic swell wrapping around the point. It is one of the better surf breaks on this stretch of coast in a solid south or southwest swell, though the seabed is sand over rock and the breaks are inconsistent. The beach to the south is more sheltered and is where most of the year-round community concentrates.

Tidal range here is 0.6 to 0.9 metres at spring tides — the mixed semidiurnal cycle produces two unequal high waters and two unequal low waters each day. The practical effect on the beach is visible: at low water, the sand extends 50 to 100 metres further than at high water, exposing the lower-gradient flats where the sea lions occasionally wander when the surf is calm. The tidal flat is rocky in places close to the headland and transitions to sand beach further north and south.

Food in Cabo Polonio is basic and expensive by Uruguayan standards — everything comes in by truck, including fresh produce and water. The half-dozen restaurants and small shops operate on tourist-season logic: fully stocked and busy from December through February, intermittent the rest of the year. A few posadas (guesthouses) operate year-round; most open only for summer. Camping is possible but infrastructure is minimal.

DINAMA (Uruguay's environmental directorate) manages the protected area. Entry to the park is controlled at the Route 10 checkpoint during the season — there is an entry fee and visitor numbers are theoretically capped during peak periods, though enforcement is inconsistent. The sea lion colony and the lighthouse are both within the protected boundary; the village itself predates the park designation.

For weather, the prevailing winds are from the southwest and south, strongest in winter (May through August). Summer brings lighter, more variable winds and the warmest water temperatures (18 to 22°C). Winter water is cooler (12 to 16°C) and the surf is larger. Fog is common in spring, especially in the early morning.

Predictions on this page come from Open-Meteo Marine, a gridded global ocean model. Accuracy is typically within plus or minus 45 minutes on timing and 0.2 to 0.3 metres on height — model-derived, not from a local gauge. The nearest reference station is the Argentine Servicio de Hidrografía Naval (SHN) Buenos Aires gauge; DINAMA Uruguay does not operate a local tide gauge at Cabo Polonio.