The act limits the liability of the ship's owner during an accident to the post-crash value of the ship. So, if you crash a ship you only have to pay, essentially, "the rest of the ship."<p>It seems like the materials with which a ship is made is irrelevant to this law, and perhaps even to its intent. The law was passed as a diuretic for the maritime shipping industry, lowering the risk in order to spur economic activity. That remains true, even for steel ships.