I am on the aft end of a big ferry and gaze at the turbulent sea we are sailing on. Suddenly there is a big wave swelling coming towards us and I warn the 2 individuals with me to brace. The wave rocks our ferry but we sail on after. Of the 2 individuals, one is a little girl who al the while stands precariously on the side railing and I keep worrying that shell fall aboard but nothing happens. I dont know who the other person was, but was a woman.