The net result is a longshore or shoreline parallel component of water and sediment transport. This past summer at Ocean City, Maryland, I noticed that the waves weren't very high at all. A wave would build up offshore, then when it was about to break it would loose its height and just blend into the water. Another thing I noticed was that you could go into the water and it would get very deep very quickly, but as you went further out it became more shallow. Offshore bars are very common along the eastern seaborad of the United States.
Larger waves break on the offshore bars leaving very small waves to wash ashore.
Behind the bars , the longshore current usually erodes a relatively deeper channel just as you have described. Offshore bares form during the winter storms when sand is pulled into the ocean.