For many years, the United States engaged in discussions with friendly nations as to the reciprocal use of ports and harbors. These discussions led to various multilateral agreements between the nations as to the configuration of oceangoing vessels and how they would be piloted. At the same time, concern over oil spills in Puget Sound led the state of Washington to impose fairly strict standards on oil tankers and requirements for the training of oil tanker pilots. In addition, Washington’s state law imposed many other requirements that went above and beyond agreed-upon requirements in the international agreements negotiated by the federal government. Are the Washington state requirements preempted by federal law?