America's unrestricted access to the Atlantic and Pacific Oceans, Gulf of Mexico, rivers, Great Lakes, and Arctic region powers domestic and global commerce. The ease of moving cargo and people beyond our coasts fuels the Nation's competitive advantage, advances trade, generates capital, and drives the domestic economy forward, in turn projecting strength abroad and safeguarding our national interests. Similarly, the biological diversity and productivity of the ocean sustains the health of coastal communities and promotes a vibrant national economy. The ocean also plays a fundamental role in the Earth system. Ensuring responsible ocean stewardship with science and technology (S&T) breakthroughs depends on a strategic Federal portfolio supported by foundational basic research. Science and Technology for America's Oceans: A Decadal Vision identifies pressing research needs and areas of opportunity within the ocean S&T enterprise for the decade 2018-2028.