Roger B wrote:What is the reason for river transports? I can be sitting in Cairo and move to any place along the river without them so why do I need them? I imagine this river movement probably represents barges and such as opposed to the stern wheeler transports. So why do I need the actual transport ships?
By using them , you provide better protection for your troops than if you use the "generic" river transport, especially if you send a few gunboats or ironclads along as escort.
They can also provide a moving supply source (for a limited duration), even if you don't turn them into depots.
Roger B wrote:And, how many troops do transports (river and ocean going) hold?
IIRC, they can hold a weight of 40. The different element types have different weights (militia and infantry weighing 1?), but you should be able to see this information in the unit pop-ups/tooltips as well as in the unit/element detail windows (again, IIRC)