Notch a boat to seek a sword

There was a man from the city of Li who was crossing a river. His sword fell from the boat into the river. He quickly marked a notch on the boat saying, "This is the place where my sword fell in. When the boat stops, I will go into the water and search for my sword from the spot where I made the notch." The boat was already moving, but the sword had not moved. Is it not suspect to search for the sword in this manner?