There is a good description of the confluence of the Zambezi and Chobe Rivers
at:
www.namibiatourism.com/namibia_regions/article.asp?IDReg=2&IDArt=17
This site, advertising a lodge on Impalila Island says that it is the only place
in the world where four countries meet:
www.islandsinafrica.com/impalila.aspx
And finally, here's a detailed map:
http://users.bigpond.net.au/morlab/chobe/kas-map1.jpg
Lowell G. McManus
Leesville, Louisiana, USA