The area of current Arkhangelsk Oblast has always been located on the trading routes connecting central Russia to the White Sea, and, in fact, in the 17th century the White Sea was the main sea export route for Russia. The whole course of the Northern Dvina is navigable, as well as the lower course of some of its tributaries, most notably the Vychegda, the Vaga, and the Pinega. The Mezen is also navigable in the lower course. The Onega is not navigable except for the two relatively short stretches because of the rapids. However, except for the lower course of the Vychegda and some parts of the Northern Dvina, there is currently very little or no regular passenger navigation on these rivers. They are used for cargo traffic though.