Zakynthos · Greece · Cave & cavern
Keri Caves
A milky sulphur layer floats inside the second cavern
Photo: Altoshipper · CC BY-SA 4.0
Keri Caves is Zakynthos's signature dive: a 75 m cavern open to the sky, entered at 12 m and rising to 5 m at its turning point, with a second cavern beyond a small arch that holds a milky layer of sulphur under the surface. Divers come for the caverns themselves and for the Mediterranean monk seal that is sometimes found inside.
Also known as Blue Cave, Schwefelhöhle Zakynthos.
Where it is and how deep
37.6479° N, 20.8411° EApproximate position — the dashed circle shows where the site lies; your operator's briefing has the mooring.
The dive
You enter the main cavern at 12 m and follow it about 75 m into the rock, open to the sky all the way, the floor shallowing until you reach the turning point at 5 m and head back out the way you came. Away from the entrance the cavern is completely dark, so a good torch is a must for every diver — and this is where the monk seal is sometimes found, eating shrimp or sleeping.
A small arch at 12 m leads into the second cavern, and this one has the site's oddity: sulphur builds a layer of milky soup about 1 m thick on top of the salt water, the reason the German catalogues list the site as the Schwefelhöhle, the sulphur cave. The wannadive listing grades two of the caves for all levels and keeps one for genuinely experienced divers only.
Outside the caverns the site carries on deeper — the listed maximum is 30 m against an average of 15 m — with no current to manage and visibility given as 10 to 30 m. Most of the interest sits shallow, though, so the dive suits a long, slow profile, and the 5 m turning point far inside makes a natural place to linger before working back to the entrance.
Marine life and season
- Seals & sea lions
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Off-season | Off-season | Off-season | Fair | Good | Prime | Prime | Prime | Prime | Good | Off-season | Off-season |
Season follows Zakynthos: Dive centres run trips May to October; the warmest water and calmest conditions come in summer, and the sea stays above 20°C into November.
Know before you go
- The caverns are completely dark beyond the entrance; a good torch is mandatory and the daylight of the exit should stay in reach.
- The sulphur layer in the second cavern is a milky soup about 1 m thick under the surface and can cut visibility to nothing — stay below it.
Questions divers ask
How deep is the Keri Caves dive?+
The main cavern is entered at 12 m and shallows to 5 m at its turning point far inside; the site's listed maximum is 30 m with an average around 15 m, and no current is reported.
Can beginners dive Keri Caves?+
Two of the caves are graded for all levels, but one is reserved for genuinely experienced divers and the interiors are completely dark beyond the entrance, so every diver needs a torch and a guide who knows the caverns.
Sources
- wannadive.net — Keri Caves — wannadive.net
- Turtle Beach Diving Center — Diving Places — Diving Center Turtle Beach
- scubago — Schwefelhöhle Zakynthos — scubago.com
- scubago — Keri Caves — scubago.com
Photo credits
- A diver silhouetted in blue light inside an underwater sea cave. by Altoshipper, CC BY-SA 4.0, via Wikimedia Commons
In The Logbook
- Diving with seals and sea lionsBig animals · 17 min read
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