From 1785 on, the Hydriote shippers began to engage in commerce, not just transport. Each vessel became its own small commercial enterprise and quickly trade with the Levant began to depend on Hydra's vessels, though not without competition from those of Spetses and Psara.
However, the plague of 1792 killed a large part of the population, and many people moved away. As a result the town was almost completely abandoned for a while. Still, by the end of the 18th century Hydra had again become quite prosperous as its vessels trading as far as France, Spain and even the Americas. Napoleon presented the island with the huge silver chandelier in the cathedral as a gesture of gratitude for the Hydriots' role in running the British blockade and so bringing food to France and Europe.
The Greek War of Independence and the decline
In the 19th Century, Hydra was home to some 125 boats and 10,000 sailors. The mansions of the sea captains that ring the harbor are a testament to the prosperity that shipping brought to the island which, at the date of the Revolution, had 16,000 inhabitants. During the Greek Revolution, the fleets of Hydra and the other two naval islands of Psara and Spetses were able to wrest control of the Eastern Aegean Sea from the Ottoman Empire.
When the Greek War of Independence broke out, Hydra's contribution of some 150 ships, plus supplies, to fight against the Turks played a critical role. The Greek admiral Andreas Miaoulis, himself a settler on Hydra, used Hydriot fire ships to inflict heavy losses on the Ottoman fleet.
With the end of the revolution and the creation of the Greek state, the island gradually lost its maritime position in the Eastern Mediterranean, igniting an economic crisis which led to a period of hardship and unemployment. The main reason was that with the creation of the Greek state, its fleet lost the privileges which the Treaty of Küçük Kaynarca and the use of the Russian flag gave it
