I can recall the time we were at a CW reenactment in Selma AL, camped right near the river. The Pettis Bridge was not oo far downstream from where we were. Late one Saturday afternoon I felt the ground shaking and a tremendous roar coming from the river. The shaking got more intense and the roar became deafening. We looked around in a sort of awe/panic mode thinking surely our time was near!! It was with great amazement that I realized it was a giant tug boat pushing a number of barges down river. The sheer power that craft must have had!! That is one of those had to be there moments that I will never forget as long as I draw breath. It was AWESOME!!