This oceanographic instrumentation development project will construct a relative gravity meter system capable of high precision measurements on the seafloor, and be deployable on a large suite of remotely operated vehicles (ROV's) and submersibles. Gravity measurements of the seafloor can be used to detect vertical deformation and mass redistribution within a network of observation stations. These measurements will contribute to our understanding of plate tectonics, seafloor strain accumulation and strain patterns. Substantial cost sharing is being provided.