The above map shows which pages of the report cover which sections of river, including those referenced in my last post.
It is important to remember the differences between the Mssúma and the Nile while trying to decide if there are any similarities. For one, the Mssúma river does not flow through a desert. There is a hot season, to be sure, but the landscape around the river seems to be more like plains with high levels of cultivation. It would have forests - possibly extensive forests - in parts.
If I had a useful description of the Ganges or the Amazon or even the Mississippi - before the US Corps of Engineers did their thing - I would look at that as well. This happens to be the most detailed report on the passage of a large river, and the obstacles faced, that I know about.
The map below shows the areas referenced in the pages immediately above. There is an extra cataract (marked "Upper Gate?") - I'm not sure if it is the gate described in the text or whether it was somehow left out of the report. The distances listed don't seem to fit...