GEOTRACES is an international study of the marine biogeochemical cycles of trace elements and their isotopes (TEIs), designed by marine geochemists to accelerate TEI research under a global program. Combining ocean sections, process studies, data synthesis, and modeling, GEOTRACES will identify and quantify the processes that supply TEIs at ocean boundaries as well as the physical and biological processes that redistribute TEIs within and between ocean basins. Constraining processes that remove TEIs from the ocean will enable complete mass budgets to be generated. Anticipated beneficiaries of GEOTRACES products include scientists studying the sustained health of marine ecosystems and their sensitivity to changes in micronutrient supply; paleoceanographers seeking to reconstruct past changes in the ocean environment, including the ocean's role in climate variability; and scientists and policymakers who seek a better understanding of the transport and fate of contaminants in the ocean. It is hoped that the experiences described here will provide helpful guidance to scientists in other disciplines who wish to advance their fields by organizing coordinated research programs.