Paddle sports will always be the best way to simultaneously exercise and savor nature, because trampolines don’t propel people quite high enough to catch sunrays in their mouths. Gulp down some fresh air with today's Groupon: for $25, you get a two-hour stand-up paddle board rental from Ultimate Watersports (a $50 value). Redeem your Groupon at either of two locations at Gunpowder Falls State Park's Hammerman Area and Dundee Creek in Middle River, Maryland.

Operated by certified instructors, Ultimate Watersports outfits aquatic explorers in all they need to navigate the waters around Chesapeake Bay. Stand-up paddle boards let boaters tired of peering over their kayak-mate's head at the natural splendor take a taller stance, using a single paddle to slalom across the rippling waves in a core-strengthening workout. Whip your flat-headed trident across choppy waters when the wind picks up at Hammerman Beach, or absorb eyefuls of lush vegetation while skimming across peaceful Dundee Creek in an area heralded by countless magazines and choose-your-own-adventure novels for its vibrant foliage, sparkling water, and cuddlesome critters.

Upon returning to solid ground, customers can step into waterfront pavilions with grills for post-kayaking picnicking. Equipment and life jackets are included with rental, and shower and changing rooms are also available, allowing guests to finally display merman costumes in a appropriately glorious setting.