Seeing as its crap for boating, here are some pics off the website Nuestros Rios Navigables. http://www.nuestrosrios.com/.
This is a fabulous looking thrash over I think 3 days looks like run what you brung.
Two pics I like, much more on the site (in spanish). Wish we had an adventure in the UK like it.......
One more pic on next post.