If you're not aware of the Beer Mile, check out the many videos on YouTube. The concept is: Chug a beer, run a lap, x4. Try to get the lowest ET.
I'm thInking BEER SLALOM. Chug a beer, ski a pass; chug a beer, ski a pass; etc. until you fail. Try to get the highest buoy count with a beer between each pass.
This is genius, right?
Designated driver, of course (for the boat, and to drive skiers home).