Diving in Greece: complete guide for divers

Greece is not just ancient ruins and island hopping. Beneath the surface of the Aegean and Ionian seas lies some of the most spectacular diving in the Mediterranean: crystal-clear water with visibility exceeding 30 metres, underwater caves and arches carved by millennia of geological activity, Caretta caretta loggerhead turtles, groupers the size of small dogs, and a handful of historical wrecks that tell stories going back centuries. Here is the complete guide to diving in Greece, from the best regions to the practicalities of planning your trip.

Why is Greece an underrated diving destination?

Greece has over 6,000 islands and islets, more than 16,000 kilometres of coastline, and some of the clearest water in the Mediterranean. Yet it remains under the radar for many divers who default to the Red Sea or Southeast Asia. The reasons Greece deserves more attention are simple: water temperatures of 18 to 26 degrees from May to October, visibility routinely hitting 25 to 40 metres, a vast diversity of underwater topography from sheer walls to swim-throughs to volcanic formations, and a marine ecosystem that includes both Mediterranean and Atlantic species.

Greece also has a unique regulatory history. Until 2005, recreational diving was heavily restricted across much of the country to protect underwater archaeological sites. This means many areas were effectively marine reserves for decades, and the marine life has thrived as a result. Since the liberalisation of diving regulations, more and more sites have opened up, and the underwater world is in remarkably good condition compared to other heavily-touristed Mediterranean coastlines.

From Brussels, Greece is about 3 hours 15 minutes by direct flight to Athens, and connections to Crete, Santorini or Mykonos add another hour at most. Budget airlines serve most Greek islands from May through October, making it a very accessible destination for Belgian divers.

What are the best diving regions in Greece?

Crete

Crete, the largest Greek island, is arguably the best all-round diving destination in the country. The south coast in particular offers dramatic underwater topography: caves, tunnels, drop-offs and walls descending to 40 metres and beyond. The water on the south coast is typically warmer and clearer than the north, thanks to its exposure to the Libyan Sea.

Key dive sites include the Elephant Cave near Chania (an underwater cave with stalactites accessible to Advanced divers), the walls of Sfakia, and the sheltered bays around Agia Pelagia on the north coast which are perfect for beginners and discovery dives. Crete's marine life includes groupers (Epinephelus marginatus), moray eels, octopuses, nudibranchs, barracuda schools and occasional loggerhead turtles.

The Cyclades

The Cyclades (Santorini, Naxos, Paros, Milos) offer a completely different diving experience. Santorini's volcanic caldera creates unique underwater landscapes of lava formations, hot vents and colourful reef walls. Visibility in the caldera can exceed 30 metres. Naxos and Paros offer more traditional Mediterranean reef diving with excellent macro life. Milos is particularly notable for its underwater caves and the vibrant colours of its volcanic rock.

The Saronic Islands

The Saronic Gulf islands (Aegina, Hydra, Spetses) are the closest diving to Athens, making them ideal for short trips or weekend diving. The area is known for several historical wrecks, including a World War II German ammunition ship. Depths are moderate (12-30 metres), visibility is good, and the marine life includes octopuses, scorpionfish, barracudas and seabreams.

The Ionian Islands

Zakynthos (Zante) is famous for its Caretta caretta sea turtle population. The island is a major nesting site for loggerhead turtles, and encounters while diving are common from June to October. The underwater topography includes caves, arches and blue holes. Corfu and Kefalonia also offer excellent diving with good infrastructure.

What marine life will you encounter in Greek waters?

The Mediterranean is sometimes dismissed as less impressive than tropical seas, but Greek waters host a surprisingly diverse ecosystem. Here is what you are likely to see:

• Loggerhead turtles (Caretta caretta): Greece hosts the largest nesting population in the Mediterranean. Zakynthos, Kefalonia and Crete are the best spots for encounters.
• Groupers: the dusky grouper (Epinephelus marginatus) is the star of Mediterranean reef diving. Some individuals in Greece have grown impressively large thanks to decades of protection.
• Octopuses: common and fascinating to watch. Greek waters have healthy populations.
• Moray eels: Mediterranean morays are found in almost every rocky crevice.
• Barracuda schools: schools of Mediterranean barracuda (Sphyraena sphyraena) are a regular sight.
• Nudibranchs: dozens of species for macro enthusiasts.
• Monk seals: the critically endangered Mediterranean monk seal (Monachus monachus) is occasionally spotted in the Sporades and around Crete. Greece hosts the largest population.

When is the best time to dive in Greece?

The diving season in Greece runs from May to October, with the sweet spot being June to September. Here is the breakdown:

• May-June: water at 18-22 degrees, excellent visibility, fewer tourists, marine life very active after winter. A great time for PADI courses.
• July-August: water at 24-26 degrees, peak tourist season, some sites busier. Best conditions for beginners. The Meltemi wind can affect northern exposures in the Cyclades.
• September-October: water still at 23-25 degrees, tourism easing, visibility at its best. Many experienced divers consider this the optimal window.

Outside these months, diving is possible but water temperatures drop to 15-17 degrees, requiring a thicker wetsuit or dry suit, and many island-based dive centres close for winter. If you want to dive year-round, Tenerife is a better option.

What certification level do you need for Greece?

Greece caters to all levels. Discovery dives are available at most dive centres in the tourist areas. Open Water divers can access the majority of sites, which typically range from 8 to 20 metres. Advanced divers will appreciate the deeper walls, caves and wrecks that require 25 to 40 metre depths.

If you are not yet certified, Greece is a fantastic place to learn. The warm, clear water and calm conditions in sheltered bays make it ideal for the Open Water course. At Dive With Lau, we offer all PADI certifications in Greece during the summer season.

How do you plan a dive trip to Greece from Belgium?

Planning a dive trip to Greece is straightforward. Here are the essentials:

• Flights: Brussels to Athens in about 3 hours 15 minutes direct. Connections to Crete (Heraklion or Chania), Santorini, Mykonos, Zakynthos or Corfu add 45 minutes to 1 hour. Budget airlines offer competitive fares from spring to autumn.
• Accommodation: Greece offers everything from budget hostels to luxury resorts. For diving-focused trips, staying near the dive centre saves time and energy.
• Wetsuit: a 5 mm wetsuit is standard for summer (June-September). In May or October, a 7 mm or a hooded vest may be more comfortable. Check our wetsuit guide for details.
• Budget: Greece is generally more affordable than other European diving destinations. For a realistic cost breakdown, see our diving cost guide.
• Diving insurance: strongly recommended. DAN Europe covers hyperbaric treatment across all Greek islands. Read our DAN insurance guide.

The bottom line

Greece combines everything a diver could want: exceptional clarity, varied topography, fascinating marine life, historical wrecks, and the incomparable Greek lifestyle above water. It is accessible, affordable and endlessly varied. Whether you are a complete beginner looking for your first discovery dive or an Advanced diver chasing deep caves and turtle encounters, Greece delivers.

Want to explore other destinations? Compare Greece with Tenerife and Malaga in our best destinations from Brussels guide.

Ready to dive Greece? Contact Lau to plan your trip. We offer PADI courses and guided dives across the Greek islands every summer.