Went 2x and my Spanish was bad. It was so easy to ride buses, find drivers, rent hotel rooms, etc. It's an easy thing to do, and most boaters traveling there don't use the guide services. I'm told it's even easier today (I went 10 years ago).

Unless you are looking to do the Class V runs, most of the stuff is fairly accessible. A ton of the runs are roadside or just have the road at the top of the gorge, so you'd just have to scramble up the mountain to get out if you need to. Lots of trails down in the river valleys and gorges as well. Just when you though you were getting remote, you'd find a suspension bridge crossing the river or a steel cable and someone hauling a cow across the gorge.