On the top deck in the moonlight, the eye could pick out an occasional flash showing silhouettes of battleships firing salvo after salvo into the coastline ahead. For two days prior to the invasion, some 2,400 16-inch shells had ‘softened-up’ the enemy. These salvos gave an awesome sound. Something like a boxcar swishing around overhead. Possible mining of the area limited the firing line to six miles offshore, and because of this distance, spotters had difficulty in pinpointing dug-in gun pits.