The island of Korcula belongs to the group of central Dalmatian islands and occupies a prominent place, both in area and population. It covers an area of 276 km2 and is the sixth largest island in the Adriatic. The length of the island is 47 kilometers, and the average width is 5.3 km between the bays of Ripna and Teklina, up to 7.8 km between the peninsula of Ratak and the bay of Prigradica.
Korcula is separated from the Peljesac peninsula by a narrow canal, which is the first of its kind, from south to north. The island of Korcula dominates the Pelješac Channel, and due to this peculiarity it was of special importance for the naval forces.