Before the invention of the inner tube, antiheroes such as Huckleberry Finn doggedly traveled waterways on soggy, oversized doughnuts. Keep your morning pastries dry and your river ride lazy with today's Groupon: for $7, you get a full day of river tubing from Tube Haus in Canyon Lake (up to a $14 value), about 45 minutes from San Antonio. Free parking and shuttle service for long floats is included. This deal is good through the end of the season (approximately September 15) and must be redeemed by 10 a.m. for Saturday floats.

Tube Haus provides a relaxing escape from the sweltering summer heat by offering two scenic tube floats down the majestic Guadalupe River. The Horseshoe Loop is a one-mile stretch of water shaped like everyone's favorite cereal marshmallow; tubers can drift lazily from one end to the other before taking a short walk to the entrance to begin it all again. Doughnut-fleet commanders in the mood for a longer ride can remain in the river for another 1.5 miles of aquatic serenity before reaching the exit area, at which point there will be a friendly shuttle bus waiting to return them safely to their base.

Canines suffering from country-music levels of loneliness will rejoice in the fact that Tube Haus welcomes all seaworthy pooches and tail-wagging family members. Alcoholic and non-alcoholic beverages are allowed, and patrons may bring their own coolers or rent one for $8. The tubing checklist is recommended reading for all prospective tubers and float jockeys. River levels are projected to stay at family-friendly recreational levels for the remainder of the tubing season, which ends September 15 (weather permitting).

Customers must sign waiver.