In the next of a series of Ocean Worlds meetings, the focus will be on the potential for silicate-water interactions to occur on Ocean Worlds beyond Earth, from a multi-disciplinary and inter-disciplinary perspective. As with past Ocean Worlds meetings, a primary motivation is to engender a cross-fertilization of ideas and expertise by soliciting contributions from both the Ocean Sciences and Planetary Sciences communities. Consequently, contributions are invited that address any aspects of this broad water-rock interaction theme, across the Planetary and Ocean Science fields, including geophysics, hydrogeology, geochemistry and microbiology. Abstracts due March 7, 2018.