Lake Tanganyika is the world's 2nd deepest and 2nd largest ( by volume) lake, second only to a lake in Siberia.  It is 420 miles long and 4,820 feet deep at its deepest.  Due to the lack of circulation at its deepest, the water there is oxygen deprived.  There is a large male croc who lives in the northernmost area of the lake who is a notorious man-eater.  (that is in Burundi, near Bujumbura!)   He is rumored to have eaten as many as 300 people from the banks of the Ruzizi River and the northern shores of Lake Tanganyika.  He measures between 20 and 25 feet in length and probably weighs in at over a ton.  Gustave is approximately 60 years old and sports 3 bullet scars on his body and a deeply wounded right shoulder blade.  The last confirmed sighting was in February of 2008 by a team from National Geographic.  Swimming anyone?  There is also a movie called Primeval based on Gustave.