White Sea–Baltic Canal waterway length is , of which are man-made. The current flows north from Lake Onega to the White Sea, and all navigation marks are set according to it. Once in Lake Onega, ships can exit the southwest shore through the Svir River (and its two locks) to reach Lake Ladoga and then proceed down the Neva River to Saint Petersburg and the Baltic Sea. Alternatively, from Lake Onega river ships can sail eastward into the Volga–Baltic Waterway. The canal begins near Povenets settlement in Povenets bay of Lake Onega. After Povenets there are seven locks close together, forming the "Stairs
Lake Onega area containing the Kondopozhskaya (, depth up to ), Ilem-Gorskaya (), Lizhemskoy () and Unitskoy () bays. To the southwest of Greater Onega lies Petrozavodskoye Onego () containing the large Petrozavodsk and small Yalguba and Pinguba bays. To the east of Zaonezhye there is a bay, northern part of which is called Povenetsky Bay and the southern part is Zaonezhsky Bay. There, deep sections alternate with banks and islands which split the bay into several parts. The southernmost part of them, Lesser Onega, is deep. All the shores there are rocky. The average depth of the lake is , and