Planning a trip?
Hotels, dive operators, gear, and how to get here are on the Cocos Island location page.
Overview
Submerged seamount 25 m below the surface, rising from the deep. Hammerhead schools in the hundreds patrol the up-current edge. Cold thermocline, surge, and current — the most famous dive in the Eastern Pacific.
Briefing note
Permit-controlled park. Liveaboard-only access.
What you'll see
4 species curated- year-roundScalloped hammerhead
- year-roundGalapagos shark
- seasonalWhale sharkPeak: Jun · Jul · Aug · Sep · Oct · Nov
- seasonalSilvertip shark
Sightings evidence
1 record on file- medium confidenceScalloped hammerhead
- Last confirmed
- Mar 2026
- Recent records
- 58 within 50 km
- Cluster months
- Jun, Jul, Aug, Sep, Oct, Nov
Schooling behavior strongest at Bajo Alcyone seamount but varies with current.
Sources & methodology
How we summarise this
We aggregate confirmed occurrence records from GBIF and OBIS within a fixed radius of each dive site. Occurrence records confirm presence and reveal seasonality clustering, but they DO NOT measure per-dive probability — there is no eligible-effort denominator. We deliberately do not publish a numeric '% chance of sighting' from this data.
Sources
- Global Biodiversity Information Facility — GBIF Secretariat
- Ocean Biodiversity Information System — IOC-UNESCO
- OBIS-SEAMAP — Duke University Marine Geospatial Ecology Lab / OBIS
- iNaturalist — California Academy of Sciences & National Geographic Society
- IUCN Red List of Threatened Species — International Union for Conservation of Nature
- WoRMS — World Register of Marine Species — Flanders Marine Institute (VLIZ)
- FishBase — FishBase Consortium
- Atlas of Living Australia — CSIRO / GBIF Australia
- REEF Volunteer Fish Survey — Reef Environmental Education Foundation
Conditions
| Month | Water | Visibility | Current |
|---|---|---|---|
| Jan | 25–27 °C | 15–25 m | strong |
| Feb | 26–28 °C | 15–25 m | moderate |
| Mar | 27–28 °C | 20–30 m | moderate |
| Apr | 27–28 °C | 20–30 m | moderate |
| May | 26–28 °C | 15–25 m | moderate |
| Jun | 25–27 °C | 10–20 m | strong |
| Jul | 24–27 °C | 10–20 m | strong |
| Aug | 24–27 °C | 10–20 m | strong |
| Sep | 24–27 °C | 10–20 m | strong |
| Oct | 25–27 °C | 10–20 m | strong |
| Nov | 25–27 °C | 10–20 m | strong |
| Dec | 25–27 °C | 15–25 m | strong |
Season calendar
Peak season highlighted · current month outlined
Gear for this site
Beyond the basic kit- Temperate-grade wetsuit — Thermocline drops to 19°C at depth even in season.
- Reef hook — Standard procedure: hook in at the up-current edge of the seamount.
- Nitrox certification — Most operators run nitrox for the long deep profiles required at 25–40 m.
Next step
Book your trip to Cocos Island
Hotels, liveaboards, dive operators, gear recommendations, and travel logistics for the whole region.
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