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Thira
together with the smaller islands of Thirasia
and Aspro
are part of a volcanic crater, which has been engulfed by the sea.
In the centre are the Kameni - Καμένη islets, the cones of later volcanoes which came into being in historical times.
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Hot springs and emissions of gas bear witness to continuing volcanic activity.
The steep caldera cliffs range in height between 200 m and 400 m, while on the outside the land falls away gradually to the sea, its fertile slopes covered with vineyards.
Yet, the island is treeless due to lack of water, though the inhabitants achieve a modest degree of prosperity through the export of wine, pulses, pistachios and tomato purée. Santorini also possesses a natural resource in the form of pozzolana
, a hydraulic cement used in structures exposed to water (harbour works, the Suez Canal).
In more recent years large numbers of visitors have been attracted to the island by its extraordinary natural structure and its excavation sites, which are among the most important in Greece, and the tourist trade has made an increasing contribution to the economy. Also - with the new Vlichada marina nearly finished (see the bottom of this page) - more and more yachtsmen visit this beautiful island.
The local volcanic field of Santorini also includes the Khristiana islands 20 km to the southwest and the submerged Kolomvos volcanoNon-volcanic rocks - which are exposed on Thira at for example Mt Profitis Ilias, Monolithos and the inner side of the caldera wall near Athinios - represent a former 9x6 km non-volcanic island similar to the neighbouring Cycladic islands of Anafi, Ios or Amorgos.
Volcanism in the area of Santorini - at that time just a small, non-volcanic island - started about 2 million years ago. In short, the important stages of Santorini's volcanic evolution:
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In 630 BCE their king, Grinos, founded a colony at Kyrene - the largest Greek colony in North Africa. Allied with Sparta at the beginning of the Peloponnesian War, Santorini was required to pay tribute to Athens from 427/426 BCE onwards. It enjoyed a measure of prosperity under the Ptolemies, when an Egyptian garrison was stationed on the island. Thereafter it came under Roman rule.
In 1207, after the Fourth Crusade, Santorini was conquered by Marco Sanudo, Duke of Naxos, and thereafter remained in Italian hands for three centuries. In 1539 Santorini was taken by the Turks; in 1830 reunited with Greece.
The volcanic force which originally built up the island round the older limestone cone of Mount Profitis Ilias and then destroyed it shortly after 1500 BCE continued to manifest itself in later centuries. The last violent volcanic phenomena, combined with earth tremors causing considerable damage, took place in 1956.
In the night of 6 April 2007 the cruise ship Sea Diamond sank near the mooring buoy beneath Fira town (Skala) after hitting a reef - just south of Kammeni islet - inside the flooded crater of this volcano and making water. The weather and visibility were ideal and these waters are well charted. On the photo on the right she is already listing while passengers are evacuated by rescue boats. With a dramatic slow movement the Sea Diamond sank nose-up surrounded by liferafts to a depth of 200 metres ending on the rocky seabed of the Santorini caldera. Several cruise ships each days visit Thira in the season. BBC News: 1, 2, 3.
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Note, that lots of charts and guides erroneously only mention one breakwater. And although the northern one (not indicated in the map below) is much shorter and not the dangerous one, it is certainly there!
Once inside, you still need a watchful eye since the entrance is quite often badly silted up and a nasty submerged block awaits you at your starboard side.
The new lighted yellow buoy reported in several guides is actually marking the extremity eastern submerged mole, keep to the west of this mark (in this chart where it reads Position Approximate.
The marina is almost finished and since recently a €20 fee is required to use the water and electricity on the quay, plus WiFi network and WC facilities on shore. The marina office is opened from 0900 to 1900: VHF channel 10 or telephone 0030 22860 82119.
Due to winter storms the entrance silts up badly and each year an extensive dredging operation is required to keep the harbour as well as the entrance at a depth of 3 metres minimum - expect depths of less than 2,5 metres.
The local rent-a-bike will bring scooters right to your yacht. Indeed the best way to explore Santorini is by scooter or motorbike. Usually, you will be able to shower at the Notos Hotel which overlooks the marina. The dishes served at the nearby Taverna Limanaki are truly delicious.
More photos and information can be found in the logbook of our trip from Athens to Milos, and in my Guide to sailing holidays and yacht charters in 8 steps.