In the Victorian era, extreme sports were limited to teatime without doilies, writing witty satires about earnestness, and riding a pennyfarthing down a mild incline. Today's Groupon would shock such staid sensibilities: for $49, you get a half-day whitewater-rafting trip from California River Adventures, Inc. (up to a $97 value, including river fees and taxes). The safely adventurous trek explores the South Fork Gorge along the South Fork of the American River, which is about three hours from San Francisco.

Groups meet at Camp Lotus for a brief orientation and safety prep before the rafting rally down to Lake Folsom begins. Ideal for all skill sets, CRA's program accommodates passengers ages seven and up. The four-hour journey shoves off into a gentle warm-up section of class-II waters to prepare for the gorge's jostling class-III rapids. Fourteen-foot self-bailing rafts equipped with first aid, river-rescue kits, and Coast Guard–approved life jackets safely seat eight passengers plus an expert guide. As a team, the boatload of adventurers navigates the water like a squirrel surfing in a washing machine, punching through white caps and splashing about wavy highs and lows along the 12-mile route. All gear is included, and participants are only required to pack products that make the trip more pleasurable (swimsuit, drinking water in a durable bottle, sunscreen, shoulder-mounted boom-box, and a dry change of clothes).

With more than 16 years of experience, well-trained professional guides freeze off worrywarts with their fearless and reliable leadership. Trips are offered Monday through Friday between Memorial Day and Labor Day and weekends before Memorial Day and after Labor Day. Choose from trips in the morning, the afternoon, or the past. All participants are required to sign a liability release, express assumption of risk, and indemnity agreement before participating.