If you're trapped in a water slide that's rapidly filling with water, most people assume they should climb back upward. But the slick surface makes that almost impossible. Instead, stay calm and try to make room for air by leaning your head back. If the water keeps rising, use your hands to press yourself ahead a bit. If you can't move, hold steady as the slide fills completely. Once the pressure balances out, you may be able to move forward and float to safety at last.