The Adriatic Sea (Mare Adriatico, Adria) is an integral part of the Mediterranean sea. The characteristic of the Adriatic sea is that it reaches deep into the land mass of Europe, between the extensive coastlines of Italy, Slovenia and Croatia, and as such it is the closest and most accessible to Central Europe. The Croatian Adriatic coast, the eastern shores of the Adriatic sea, is the most intricately indented part, with a total of 1185 islands, islets and reefs, with a total coastline length of 5.835 km, a surface area of 138.595 km and its greatest depth being 1330 m (Southern Adriatic Depression) and with waters that are exceptionally transparent to a depth of 50 m, that’s why the well known summer Adriatic beach attracts so many people.
Sea temperature fluctuations throughout the year: in winter months temperature ranges from 7 to 10 C, in summer months average surface temperature is from 21 to 26 C, while the temperature at a depth of from 20 to 30 m (average diving depth) remains constant throughout the year, ranging from 16 to 17 C. Salinity is 38.32 per mille; the difference between high and low tide varies from 40 cm (Southern Adriatic and Dalmatia) to 1m in Istria. The Adriatic is a relatively calm sea, with no high waves or strong currents. Wave height ranges from 40 to 150 cm, and to 4 to 5 m at the most in extremely adverse weather conditions on the open sea. Speed of sea currents is about 0.5 knots, although in certain places and in special weather conditions it can reach up to 4 knots.
Since times immemorial the Adriatic Sea has been the shortest maritime route leading from the Central Mediterranean and the cities of great civilizations of Antiquity towards northern lands and Central Europe. Having been such a vital route down the ages, both on land and beneath Adriatic’s blue waters can be found deep-seated traces from all periods of the development of European and world civilizations.