Brazil · Southeast Brazil

Arraial do Cabo

Cooler upwelling season is favored for visibility and marine life.

Arraial do Cabo on Brazil's Rio coast sits where cold upwelling current meets the tropical Atlantic — a strange biogeographic boundary with unexpected biodiversity, schools of jacks, and the country's most accessible diving from a major city.

Good season

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

December–March is warmest; July–September has cooler water but better pelagic action.

Trip duration

2–3 nights as part of a Rio trip.

Dive style

Boat diving on rocky points; moderate current.

Dive level

Open Water; Advanced for deeper sites.

Reef health

What you’ll actually find
Mixed

Some loss since the 2010s, but the reef still has plenty to dive. Pick depth and shoulder-season carefully.

Heat stress right now

No stress

No abnormal heat right now. Corals stay coloured.

NOAA Coral Reef Watch · updated May 2026 · 1.1 °C-week heat dose

What to expect on a dive

Cold-water upwelling drives extraordinary visibility seasonally. Subtropical fauna; not a tropical reef ecosystem.

Sources, methodology, and the raw numbers

Raw observed numbers

  • Coral cover: 30% (survey Sep 2024, Local temperate-reef benthic transect)
  • Bleached: 2%
  • Recent mortality: 1%
  • Temperate reef — observed condition reflects the stable regional pattern.

Raw thermal numbers

  • NOAA CRW alert level: No stress
  • Degree Heating Weeks: 1.1 °C-wk
  • SST anomaly: +0.1 °C

How we summarise this

Observed coral cover, bleaching, and mortality come from named in-situ surveys with a stated date and method — they describe one snapshot of one reef and do not extrapolate to neighbouring sites. Current thermal stress is satellite-derived from NOAA Coral Reef Watch at ~5 km resolution; it indicates risk, not observed coral damage. We deliberately separate observed condition, current thermal stress, and projection — and we never publish a projection without a documented model and uncertainty.

Sources

Reef condition changes year to year. If you visit, consider supporting responsible-travel and conservation operators on the ground.

Pressure on this reef

Protection · fishing · what you can do

Protected-area status

Multi-use MPA

Inside a designated MPA that permits regulated fishing and other uses. Worth checking which zones at this location are no-take.

Fishing pressure

Moderate fishing pressure

Dominant pressures

  • pelagic fishing
  • warming
  • limited monitoring

1 Green Fins-verified operator known at this location.

What you can do

Atlantic island reefs (Azores, Canaries, Cape Verde) are partially protected. Pelagic fishing pressure dominates; pick operators that support marine-science partnerships.

Protection status sourced from Protected Planet / WDPA and refined with Marine Protection Atlas. Fishing pressure proxy is Global Fishing Watch AIS data. See the methodology for what these sources can and can’t prove.

Dive sites here

1 curated

Gear

What to bring

Basic kit

What divers say

Cold-water upwellings 2h from Rio give you fish you wouldn't expect at that latitude.
Local divemaster