The Virgin Islands Coral Reef National Monument (VICRNM) was created to expand the protection of the marine ecosystems around St. John. Monument boundaries were not designed using ecological criteria, but were instead the result of historical land ownership and the Territorial Submerged Lands Act of 1974. This study used acoustic telemetry to investigate movements of reef fish relative to the boundary of the Coral Bay portion of the Monument and the protection that this Marine Protected Area (MPA) could offer. In this approach, acoustic transmitters are implanted into fish and their movements are logged on battery-powered acoustic-receivers (n=38) positioned within, outside, and along the boundary of the Monument. Specifically, we quantify residence time of reef fish within VICRNM, the frequency of movements across the VICRNM boundary, and locations of concentrated fish activity. The National Park Service (NPS) manages the entire reef fish community within the Monument. Therefore, we set fish traps in various habitats throughout VICRNM to capture a diversity of species for tagging. Uniquely coded transmitters with a ~376 day battery life were implanted into 75 fish between August and December 2013. Minimum fish size was ~20 cm to accommodate tags. The fish tagged were from 17 species in 7 families with snappers (n = 38 fish) and grunts (n = 24) being the most common. Receivers were downloaded March 2015. Data were summarized to convey basic information about fish movements including: the timespan of detections, number of detections, percent of days detected, number of receivers visited, number and frequency of VICRNM boundary crossing events, proportion of detections inside versus outside VICRNM, and location of day versus night detections.