“How much of the river is navigable? Certainly not all 1200 miles.”
Actually not much. Probably a few stretches of a couple of miles or so. But . . .
I’m not so sure that it’s a bad idea. Given the level violence that’s been going on near the border - a bit more fire power on a few strategically placed “coast guard” stations might be a good idea.
If we’re going to do that, we should just get the TNG to do it. Coast Guard has enough jobs without having to monitor an internal river, and I wonder if it might violate the Passe Comitatus Act.
The entire river is “navigable” - if you think outside of the box
Like these folks
http://www.hovercraftalaska.com/
Some high speed hovercraft, lightly armed (240G or SAW) tied into a helo response force - fewer Mexicans (and Chinese, Arabs, etc, etc) flooding thru the border.
And who knows, it might even be - fun....OK for a little while anyway.