Imagine coming face-to-face with an elephant seal during an underwater dive. The bull attacks -- but what would you do? Dive deeper and hope it gives up? Or fight back? Nat Geo Channel breaks down this and other life-threatening moments to present the best options for survival. Dive headlong into a crisis when a huge yacht slams into your tour boat. And think fast or be crushed as your Jeep rolls down a steep, rocky embankment. Life-or-death moments can happen anywhere. What would you do?