Scuba Season
Underwater reef at Catalina Islands
Declining

Catalina Islands

Costa Rica · Guanacaste

The Catalinas off Costa Rica's Guanacaste coast are seasonal manta and bull shark country — volcanic pinnacles in nutrient rich Pacific water, accessed by 30–45 min boat from Playas del Coco.

How this reef is doing

How we measure this

Reef state

Declining

Bull sharks, mobulas, rays. Eastern Pacific reef ecology is naturally low coral compared to Indo Pacific reefs.

Coral cover

27%
LowHealthy
Moderate

Fish life

Not surveyed

Heat

SafeBleaching

Hot enough that coral is bleaching now.

Bleaching now

Fishing

QuietBusy

Quiet water, and the protection is actively patrolled.

Patrolled

Sources · Reef survey · NOAA Coral Reef Watch · Global Fishing Watch and reef gravity

Coral cover over time

Live coral cover, by survey year

Across surveys in 2014 and 2024, live coral cover here has fallen from 32% to 27%. Every point is a real survey reading, never a projection.

Live coral cover, percent by year

40%0%region avg 23%20142024
Two surveys
Eastern Tropical Pacific average (GCRMN)
Reef survey

What you will see

11 species across the dive sites here

Dive sites

What divers say

Pacific Costa Rica isn't the prettiest water, but the manta odds in August are absurd.
Local divemaster

Good to know

Water temp swings

Thermoclines can drop 8°C. 5mm and a hooded vest are sensible.

Gear & getting wet

  • Basic kit

    • Mask and fins
    • BCD and regulator
    • 7mm wetsuit or drysuit · cold water
    • Dive computer
  • For specific sites

    • Temperate wetsuit · La Pared (The Wall)
    • SMB + reel · La Pared (The Wall)