I didn't realize it until staring at this picture for a while. Those pilings were too short. I'll bet that the storm surge lifted those floating docks right up over the tops of the pilings. Pilings should be 12 feet higher than the highest tide.
Reviewing the picture below, the tops of the pilings appear to be only 7 feet higher than the water. I can't tell if the picture was at high tide or low tide.