In the summer of 1803, Thomas Jefferson sent Meriwether Lewis and William Clark on a journey to establish an American presence in a land of unqualified natural resources and riches. Is it fitting that, on the 200th anniversary of that expedition, the United States, together with international partners, should embark on another journey of exploration in a vastly more extensive region of remarkable potential for discovery. Although the oceans cover more than 70 percent of our planet’s surface, much of the ocean has been investigated in only a cursory sense, and many areas have not been investigated at all. Exploration of the Seas assesses the feasibility and potential value of implementing a major, coordinated, international program of ocean exploration and discovery. The study committee surveys national and international ocean programs and strategies for cooperation between governments, institutions, and ocean scientists and explorers, identifying strengths, weaknesses, and gaps in these activities. Based primarily on existing documents, the committee summarizes priority areas for ocean research and exploration and examines existing plans for advancing ocean exploration and knowledge.