The water seems even colder the second time and almost forces the extra air from Reid's lungs as he swims hard toward the tunnel. He reaches the lip just as panic sets in. Maybe he should surface, take another gulp of air? But he is already being drawn in by the current and has no choice.

He swims as best he can in the narrow way, finding it widens as he goes, the undertow slowing. Reid realizes they were lucky the front end is a bottleneck. It creates enough pressure to make ...