Before humans settled on rubber tubes, alternative flotation devices such as fainting couches, big shaggy dogs, shards of the Pequod, and an extra-large roll of absorbent paper towels all enjoyed their moment in fashion. Today's Groupon gives you a chance to test the unparalleled innovation out for yourself: for $7, you get an inner-tube float for up to four hours on the Guadalupe River (a $15 value) with Whitewater Sports Tubing. This deal is valid Sunday through Friday. Today's deal includes shuttle service upriver and/or pick-up downriver, and, of course, the requisite tube.

Floats last between one and four hours each, and the short, one-hour route can be repeated. Gather a team of water-drawn hooligans for a relaxing journey that takes you around the famous Horseshoe Loop. The river is flush with Momma Nature's finest currents and rushing at its highest level in three years, so there's no better time to propel yourself and your professional water Marco Polo team down a living waterslide. Choose the route that will satisfy your inner sundial and outer sunsoaker.

If you bring a crew of four or more, Whitewater Sports will offer a complimentary cooler tube, perfect for adult sodas or globules of Capri Sun. Slip an inflatable quarter into this whitewater rollycoaster and explore the natural world from the comfort of a gently floating inedible donut with today's Groupon to Whitewater Sports Tubing.