
As for all communities established along the coastline
sea, related techniques, such as shipbuilding, seafaring, as well
as fishing, were developed in Greece from the down of the history.
Greeks established very strong ties with the sea and soon they
become a tremendous sea power. Bold discoverers visited in their
ships the entire known ancient world and they established commercial
relations with distant nations. The nautical supremacy of the
Athenians, with their warships the "TRIREMS" -that bore
three rows of oars as well as a metallic ram projecting from the
bow- enabled them to withstand victoriously the assault of outnumbering
Persians who wanted to enslave them. It is thanks to their maritime
valor that they established trade colonies throughout the then
known world.
Simultaneously Greeks discovered at a very early
stage the immense wealth of the sea bed and consequently fishing
and free diving developed greatly. The free divers of that ancient
world were not used only for nourishment needs but also for war
purposes. Thus they formed a precious part of warship crews. Most
of the existing reports relating to these times give evidence
of the feats of these diving warriors. As was then customary,
heroic duds were divined and thus the names of heroes were added
to mythology. Thus besides Poseidon, the God of the sea and master
of the fate of every seaman, Greek mythology refers to the astounding
diving achievements of GLAFKOS.

SKYLLIS and YDNA
In Herodotus SKYLLIYS the Skionian (from Skiona in
Halkidiki) is referred to as " a superb diver" and it
is mentioned that he dived in the deepest parts of the sea. He
taught the diving techniques to his daughter YDNA. At the beginning
SKYLLIS was an ally of the Persians and he partook to their expedition
against the Hellenes. When the Persian flute shipwrecked an the
shores of Pilion, he dived and recuperated valuable objects from
the sunken ships, but kept however for himself some of the most
valuable. Thus he lost the Persians favor and had to escape by
swimming (oft underwater) the distance of 80 Stadius (approx.
15 km). With his daughter's help he succeeded in destroying the
remainder of the Persian Ships and , diving below, they cut their
anchors and all safety means. In their honour the "Amhiktyons"
erected their statues at Delphi. The statue of YDNA was subsequently
taken away to Rome by the Roman emperor Nero, whereas the statue
of SKYLLIYAS stood there up to the year 170 A.C.
It should be particularly noted that Herodotus mentions, as regards YDNA, that only virgin women were allowed to practice the diving art in antiquity.
References as to the feats of divers for military purposes, making No mention of any particular ones, are made by Homer in ILIAD - Rhapsody verses 733-750 ,"truly, the Trojans have in their ranks such capable divers?" as well as by Thoukididis in SIKELICA, 7th book, chapter 25 where referring to the siege of Syracuse by the Athenians, he describes the method and the endeavors exerted by the Athenian divers to destroy the underwater defensive barriers of the harbour.

The resort to divers for clearly military operations is also mentioned to have taken place in the course of the battle of Thermopiles when the Greek leader Leonidas sent a special corps of divers to kidnap the Persian emperor from his headquarters, considering that the only way to reach the Persian encampment was via the sea. Although the raid was a success, the Persian emperor was not captured as he was not in his quarters that night.
The tradition of sponge collection, with their unbelievable feats, spread to many Greek islands, but its main representatives are the inhabitants of Kalymnos and Symi. It is said, though this has not been ascertained, that Alexander the Great dived, and remained underwater for a long time, using a crystal bell. (shortly before his unexpected death, making some experts to speak about decompression sickness).
The first recorder descent, made with the use of
an autonomous apparatus, is that of a women, called EVGENYA MASTORIDI,
wife of PHOTIOS MASTORIDIS, and effected in the isle of Symi in
1863. Her husband was a renowned sponge diver and he brought in
Greece the first scaphander. As his country men were not easy
to convince to try the new equipment, which considered risky,
his pregnant wife wore it and dived at the entrance of the harbour.
The use of such diving "wear" spread throughout these
two islands and brought wealth to its inhabitants. However it
also brought the terrible and then yet unknown diver's sickness,
up to these days one can meet on the island of Calymnos one of
these former "mechanics" (as these autonomous divers
were then called) hit by the paralysis caused by this accursed
foe.

Particular attention should be given to the story
of STATHIS HADZIS, the firs man ever to dive freely to a depth
of over 80m. Hadzis was a famed diver of the island of Symi.
The captain of an Italian warship called the "Regina Margherita"
asked him to recover his vessel's anchor that had been lost at
cape Pigadia off the island of Karpathos. On 16 July 1913, in
the presence of the entire crew of the warship, he effected the
unbelievable immersion to a depth of 88m., just holding a stone
in his hands that dragged him to the bottom swiftly. When in the
darkness of the abyss , he succeeded in locating the lost anchor,
he tied to its chain a wire which he was carrying round his waist.
The whole operation lasted 3min and 58 seconds, as recorded by
the ship's officers. Hadzis was upon his ascent examined by doctors.
He was vainly trying to tell them that it was only underwater
that he had the ability of holding his breath for such a long
time. This unbelievable feat by Stathis Xadzis was recorded in
the ship's log. The story became known throughout the world thanks
to two persons: the modern world champion in deep diving Jacque
Mayol and a former sailor of the warship who attained in 1950
a high ranking position in the Italian Admiralty.
(Bibliography: Mythology of Gods and Demons/ The
Conqueror of the immense Blue G.Detorakis/ relevant books : Pafsanias
9,22,6-7/Athineos 7.296-297/Filostratos.Icons2/ Commentaries of
Platon/The Barbarians by K.Plevris)