Without floating tubes, the world's rivers may have never turned lazy, and the oceans would have forever remained salty. Celebrate Mother Nature's gift to herself—flotation—with today's deal: for $8, you get one four- to five-hour float trip (a $16 value) with Tubing and Adventures. Trips launch every Saturday from the West Maple Road Canoe Landing near Waterloo and take a bus ride upriver, before enjoying a one-way float downstream back to the village. This Groupon does not include a $5 deposit that will be refunded at trip's end if all equipment is returned intact, you say please, and these conditions are met.

Lie back and slow down on an inflated cloud of relaxation as you float down the Elkhorn River with tube-loads of friends, food, and summer thirst quenchers. Bring whatever you desire to add some fire into the weekend waterfest: waterproof radios, waterproof watches, and waterproof children are all welcome aboard. The journey usually lasts between four and five hours from start to finish, so you'll have plenty of time to finish off a few 24-packs of strawberries with your floatmates.

Whether you're a laid-back river rat with a yearning for the summer sun or a published scientist researching recent spikes in aquatic partying, you'll have no trouble kicking back in your tube. There's no purchase limit, so feel free to break the world record for number of people simultaneously slow clapping while fist pumping in tubes. You also have the option of redeeming this Groupon for the Sunday short float (normally $12), which departs from the same Waterloo landing.

Anyone under the age of 16 must be accompanied by an adult, and customers under 18 must have parental permission to rent a tube. This Groupon is subject to river conditions; call ahead to verify safety.