River movement of assault force

[Heldenkaiser]

If I have a force already on the ground in the region with a fort in it, and I move a second force there using "normal" (abstracted) river transport rather than embarking on explicit transport boats, what will happen? If the river movement path does not move past the fort (in which case I understand the embarked force would be fired upon and suffer, but wouldn't the same happen with explicit transports?).

Does my military control in the target region matter?

Thanks!

[Bertram]

Forts will fire upon traveling troops using general transport. Not only when passing the fort, but also when using the river adjacent to the fort to cross, and (I think) when landing in a region adjacent to the fort.

I had a division crossing from Clarcksville to Humphrey's, and the enemy forts Henry and Donaldson shot at my force twice.

(I didnt expect this, it looked like there was some distance between Clarcksville and the Forts-like 50 miles or so. But the river region actually runs from Clarcksville to the Fort(s). Cost me 89 hits, and took the fight right out of the division.)