Until the personal watercraft was invented, mankind's only hope for summer fun involved hitting candied hams with tree branches. Today's Groupon celebrates watery invention: for $40, choose between a one-hour weekend WaveRunner rental or a two-hour weekday rental from Millerton Lake Rentals (up to a $125 value).

Ten dollars per vehicle gets aspirant aquanauts into Millerton Lake State Recreation Area, where Millerton Lake Rentals equips them with aqua machines proficient enough to etch waves across the glassy pool. Though other businesses may offer less expedient yet inexplicably popular walrus rentals, this is the only boat rental on Millerton Lake, so the waterways remain comfortably uncrowded for frolicking in the pristine waterways. The Yamaha WaveRunner VX 110 Deluxe seats three, boasts 110 horsepower, and, with a top speed of 56 mph, can easily outrun troves of jealous, pitchfork-wielding fish. After exploring the more than 40 miles of shoreline from the wet side, nature lovers can make an afternoon of hiking the surrounding hills.

Tax and fuel is not included.