Diagram by Greece Trips. Free to reuse with credit - CC BY 4.0.
What the water is actually like
- Visibility is excellent, often 20 to 30 metres and sometimes more, because the eastern Mediterranean is nutrient-poor.
- That same poverty is why the fish are sparse. Nutrient-poor water is clear water and thin water. You will see bream, damselfish, octopus, moray, occasional grouper and, if you are lucky, a Mediterranean monk seal at distance.
- Temperature runs from the mid-teens in winter to the mid-twenties Celsius by late summer. Summer diving is comfortable in a shortie; spring and autumn want a full suit.
- The topography does the work: walls, caverns, swim-throughs, boulder fields and drop-offs, all volcanic or limestone.
The archaeology, and why it was closed
Greek waters were largely closed to recreational diving for decades, precisely because of what is on the seabed: the country protected its underwater antiquities by keeping divers out of most of the coast. The law was progressively liberalised, and diving is now permitted across most areas, with defined protected zones still off limits.
That history has an upside. Sites here have not been picked over.
More recently Greece has opened a small number of ancient wrecks as visitable underwater sites, the best known being the classical cargo wreck off Alonissos, in the national marine park, where a field of amphorae lies on the seabed and access is regulated and guided.
Where people dive
- Alonissos and the Sporades: the marine park, the amphora wreck, and the monk seal population.
- Santorini: volcanic walls, black rock and a caldera that drops away underneath you.
- Milos: caverns, arches and the same volcanic geology that shapes the coast above water.
- Crete: the widest choice of operators and a scatter of second world war wrecks.
- Zakynthos and Kefalonia: caves and clear Ionian water.
- Chios, Kalymnos and the Dodecanese: quiet sites and a serious diving heritage, since Kalymnos was the sponge-diving island.
Practical notes
- Dive with a licensed centre. Independent diving is restricted in many areas and centres know which zones are closed.
- Bring your certification card and log. Centres check them.
- Nothing comes up. Removing anything from the seabed, and especially anything ancient, is a serious offence rather than a souvenir problem.
- Season: centres run roughly April to November, with the warmest water in August and September.
- Flying: leave the usual interval between your last dive and a flight home, which matters here because most trips end with a plane.
Last checked August 2026. Access rules and protected zones change - see our editorial policy.
Common questions
Is diving in Greece good?
Yes, for visibility, underwater rock formations and archaeology. It is poor for reef life, because the eastern Mediterranean is nutrient-poor, which is the same reason the water is so clear.
Why was diving restricted in Greece?
To protect underwater antiquities. Most of the coast was closed to recreational divers for decades, and the law has since been liberalised with defined protected zones still off limits.
Can you dive on ancient shipwrecks in Greece?
At a small number of regulated sites, yes. The best known is the classical cargo wreck off Alonissos inside the national marine park, visited with a guide.
What is the water temperature for diving in Greece?
From the mid-teens Celsius in winter to the mid-twenties by late summer. A shortie is enough in August; spring and autumn want a full wetsuit.
Where is the best diving in Greece?
Alonissos for the marine park and the wreck, Santorini and Milos for volcanic walls and caverns, and Crete for the widest choice of operators.
Next
Read Alonissos, Milos, or what the sea is like.