Do it yourself tubing on Guadalupe River?

my family wants to tube on the guadalupe but without paying for an outfitter. We have tubed once on the comal and we used rockin r. it was great and easy but this time we just want to do everything by ourselves. what are the access points and different options. I know there is a horseshoe route. we are looking to float for maybe 3-4 hours. this website is useful a href="http://www.tubetexas.com/" rel="nofollow"http://www.tubetexas.com//a but it doesnt give the access points for the guadalupe. any tips would help!