Onega Bay Onega Bay The Onega Bay () is located in the Republic of Karelia and Arkhangelsk Oblast in Northwestern Russia, west of the city of Arkhangelsk. It is the southernmost of four large bays and gulfs of the White Sea, the others being the Dvina Bay, the Mezen Bay, and the Kandalaksha Gulf. The area of the bay is . The Onega Bay is long and - wide. The average depth of the bay is , and the maximum depth is . The bay freezes in winter. Onega, Kem, and Vyg Rivers flow into the bay. The bay has numerous islands.
Arkhangelsk Oblast the south-west of the Oblast drains into the Kema River which belongs to the basin of the Caspian Sea. The area in the Onega River basin containing the biggest lakes in the oblast, such as Lake Lacha, Lake Kenozero, Lake Undozero, and Lake Kozhozero. The tundra of the Nenets Autonomous Okrug also contains a number of bigger lakes. The river basin of the Pinega is characteristic of the karst, with a number of caves in the region. The White Sea coast within the Oblast is split into the Onega Bay (where the Onega is the major tributary), the Dvina Bay