Dive site · access from Cocos Island
Bajo Alcyone
Named after Cousteau's Alcyone; divers drop to a plateau around 25 to 30m and hold on to watch hammerhead schools pass over the seamount.
- Depth
- 25–40m
- Current
- Strong
- Minimum level
- Advanced open water
- Access
- Boat
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The case for it
Why dive here
- Submerged seamount, Cocos's top hammerhead site
- Permanent shot line for a fast negative descent into current
Check before booking
What may rule it out
- Advanced open water certification is the stated minimum.
Access and timing
Plan this through Cocos Island
Best overall months: Jun, Jul, Aug, Sep, Oct, Nov. Check the destination planner for operating season, wildlife and other matching sites.
Wildlife
Seen around Cocos Island
rareoccasionalcommonly seenpeak seasondestination closed
These are destination-level records, not confirmed sightings at Bajo Alcyone.
Giant oceanic manta ray
| Month | Likelihood |
|---|---|
| January | occasional |
| February | occasional |
| March | occasional |
| April | occasional |
| May | occasional |
| June | occasional |
| July | occasional |
| August | occasional |
| September | occasional |
| October | occasional |
| November | occasional |
| December | occasional |
Tiger shark
| Month | Likelihood |
|---|---|
| January | occasional |
| February | occasional |
| March | occasional |
| April | occasional |
| May | occasional |
| June | occasional |
| July | occasional |
| August | occasional |
| September | occasional |
| October | occasional |
| November | occasional |
| December | occasional |
Whale shark
| Month | Likelihood |
|---|---|
| January | rare |
| February | rare |
| March | rare |
| April | rare |
| May | rare |
| June | occasional |
| July | peak season |
| August | peak season |
| September | peak season |
| October | occasional |
| November | rare |
| December | rare |
Bigeye trevally
| Month | Likelihood |
|---|---|
| January | commonly seen |
| February | commonly seen |
| March | commonly seen |
| April | commonly seen |
| May | commonly seen |
| June | commonly seen |
| July | commonly seen |
| August | commonly seen |
| September | commonly seen |
| October | commonly seen |
| November | commonly seen |
| December | commonly seen |
Scalloped hammerhead shark
| Month | Likelihood |
|---|---|
| January | commonly seen |
| February | commonly seen |
| March | commonly seen |
| April | commonly seen |
| May | commonly seen |
| June | commonly seen |
| July | commonly seen |
| August | peak season |
| September | peak season |
| October | peak season |
| November | commonly seen |
| December | commonly seen |
Nearby alternatives
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Sources & last checked
Checked July 2026
Research is source-backed, but conditions and fees should still be confirmed locally.
View 2 sources and checking notes
- A Guide to the Dive Sites of Cocos Island, Aqua-Firma
- Cocos Island Diving, Costa Rica, Dive The World
Note on the data: Coordinates are approximate; not surveyed dive-site GPS.