Arraial do Cabo

The water at Arraial is a different colour from the rest of the Rio coast, and there is a physical reason for it: the coastline turns sharply here and prevailing winds push surface water offshore, drawing cold, clear, nutrient-rich water up from depth. That upwelling keeps visibility high, keeps the sea cold enough to surprise people who expect tropical warmth, and supports a food chain dense enough that Arraial is the main diving base in south-east Brazil. Boat trips run to Praia do Farol on Ilha do Cabo Frio, to the Gruta Azul sea cave and to Prainhas do Pontal do Atalaia, which is reached down a long staircase. Salt pans and an old soda-ash works sit at the edge of the town, which is less picturesque than the beaches suggest.

The landscape

• Upwelling-clear water - cold water drawn from depth, keeping visibility high.
• Praia do Farol - the island beach reached only by boat.
• Gruta Azul - the sea cave entered by small boat at calm tide.
• Dense marine life - the reason this is the region's main dive base.

When to go

December to March for warmth. Two days. Visibility is good all year.

Things to know

The sea is cold - often under twenty degrees - which catches people out. Boat trips are heavily sold and can be crowded and loud. Access to Praia do Farol is capped and closes in rough weather. The town is industrial in parts.

Nearby

Cabo Frio is next along the coast; Buzios is north-east.