Ferromanganese crust samples were collected via dredge during four oceanographic research cruises to the western equatorial Pacific Ocean. The location (latitude, longitude, depth) and concentrations of 27 major and trace elements in the most recent growth layers of ferromanganese crusts from 57 dredge sites are presented here, as well as select seawater chemistry at each location. These data were used in statistical analyses to determine how oceanographic conditions affect the chemical composition of ferromanganese crusts throughout the region. The changes in ferromanganese crust composition show that modern measurements of these primary oceanographic parameters, as well as paleoceanographic reconstructions, can be used to define regions of interest for FeMn crust exploration.