At the top of the Summit Plummet waterslide at Walt Disney World's Blizzard Beach in Orlando, Florida—which stands some 120 feet (37 meters) above the ground—thrill seekers have been known to turn ...

Schlitterbahn co-owner Jeff Henry struck on the idea some time around 2012: His Texas company would build a water slide zipping riders from a height nobody had gone to before. The notion looked ...