Congress enacted a federal statute called the Ports and Waterways Safety Act that established uniform standards for the operation of boats on inland waterways in the U.S. The Act coordinated its provisions with those of foreign countries so that there was a uniform body of international rules that applied to vessels that traveled between countries. Pursuant to the act, a federal rule was adopted that regulated the design, length, and size of oil tankers, some of which traveled the waters of the Puget Sound area in the state of Washington. Later, the state of Washington enacted a statute that established different designs, smaller lengths and smaller sizes for oil tankers entering Puget Sound. Oil tankers used by the Atlantic Richfield Company (ARCO) met the federal standards, but not the state standards. ARCO sued to have the state statute declared unconstitutional. What result and why? Hit: Under Supremacy Clause