The Amvrakikos Gulf, a semi-enclosed embayment in Northwestern Greece, is approximately 35 km long and 6-15 km wide. Its maximum depth is 65 m, and it is separated from the open Ionian Sea by a beachebarrier complex. The Gulf and the Ionian Sea are connected through a narrow, elongated channel, the Preveza Straits, that is approximately 6 km long and ranges in width from 0.8 to 2 km. The channel at its entrance is approximately 2 km wide and gradually narrows, reaching a width of approximately 0.8 km at the mid-channel. The sill depth over this distance is between 2 and 10 m, including a man-made navigational channel. Past the middle, the channel gradually widens reaching a width of approximately 2.5 km, and the sill deepens to approximately 20 m.