the bay into several parts. The southernmost part of them, Lesser Onega, is 40 - 50 m deep. All the shores there are rocky.

The average depth of the lake is 30 m, and the deepest spot of 127 m is located in the northern part. The average depth is 50 - 60 m in the middle and rises to 20 - 30 m in the southern part. The bottom has a very uneven profile, it is covered with silt, and contains numerous trenches of various size and shape in the northern part. The trenches are separated by large shallow banks. Such