Profile: River Congo

By Mark Doyle
BBC News

The boat disaster on a tributary of the River Congo, in which over 160 people were killed, involved two of the very large ferries that ply the waterways of the region.

The ferries in the area are large and often overloaded because of the Democratic Republic of Congo's unique geography and political history.

The long time ruler of DR Congo, Mobutu Sese Seko, who held power for nearly four decades until 1997, built hardly any roads or railways in his vast fiefdom.

Cars and trains can be used by armies, and armies on the move can mount a military coup.

So apart from prohibitively expensive air travel, the only way for most people to travel between the west and the east of DR Congo is on the big ferries which ply the 4,380km-long Congo River.

River rebels

It flows from the capital Kinshasa in the west, in a great arc through impenetrable jungle, to the mining city of Kisangani in the east.

Boats are the cheapest form of travel in DR Congo

The river is so strategically important that for several years, during the Congolese civil war, boats were banned from it because the authorities in Kinshasa thought it could be used by advancing rebels.

And in fact the location of the capital itself is also determined by a physical aspect of the river.

The waters of the Congo crash into a huge series of rocks at Kinshasa, which is some 400km from the mouth of the river at the Atlantic.

The rocks are known as the Cataracts and are quite immoveable.

Their presence means the Congo river is navigable from Kisangani to Kinshasa but not beyond there to the ocean.