Description: The Construction Survey Measurements (Dredge Area Survey Data) Mosaic Dataset is a collection of pre- and post-dredge bathymetric data in raster format that were gathered as part of Outer Continental Shelf (OCS) dredging activities associated with authorized leases maintained by the Bureau of Ocean Energy Management (BOEM), part of the U.S. Department of the Interior. Entities are authorized to dredge sand, gravel or shell resources from the OCS after entering into a Negotiated Non-Competitive Lease or Memorandum of Agreement with BOEM. As part of the lease agreement lessees are required to conduct pre- and post-dredge bathymetric surveys over the entire footprint of the authorized lease area and typically occur within 90 days of dredging activity; actual time frame specified in stipulations found in a Negotiated Non-Competitive Lease or Memorandum of Agreement with BOEM. Units, horizontal/vertical datums, instrumentation used, and associated project ID are listed as summary attributes for each raster. Updates to this dataset will occur regularly as leases are added or renewed and when further dredging activity occurs. Area covered: U.S. OCS (primarily 3nm to 12nm offshore). Each raster in this mosaic is stored in its native projection. The rasters are projected into NAD83 on the fly by the MMIS WebViewer. Should a user export a raster from the database, or download it through the viewer, the downloaded file will be in the native projection.