Multinational forces storm Mayport beach for drills

Sailors and Marines along the beach at Mayport began moving the crowd away from the water Saturday afternoon as the amphibious assault vehicles approached across the waves.

"Everybody back up!" a sailor shouted. "Keep backing up. Now move back just a little more."

Moments later, the vehicles - looking like the offspring of a submarine and a tank - burst through the surf, surging forward as their treads bit into the sand.