Hey just wanted to throw in some feedback. I plan(ned) on tubing all the rivers this summer - guadalupe, comal, frio, the works. Well every time I'd go my family would be the only ones without an ice chest radio, and i didn't want that to happen again.
I started to build my own, but it was a mess. Then i tried posting on craigslist and looking around, but couldn't find one.
Turns out there was a company here in Texas that builds them, at www.TexasRiverradios.com
... i got one from them, and it's been great! Used it once so far this summer but the battery lasted the whole day (8 hours!!) and still kept on going! It was a huge hit, and still affordable.
Some of the radios you guys have posted look great! I would have loved to try to build one myself, but if you ever just want to pay someone for one, i think the TexasRiverRadio.com place is good - it worked for me.