.PDF - Portable Document Format; Shows map of plotted survey data and other information including horizontal and vertical datums, vessel and crew names, sounding frequency, etc.
.XYZ - ASCII text file; Comma-delimted and contains 3 columns for eastings, northings and elevations in that order for each survey point associated with cross-sections of that survey sheet in most cases. The .XYZ file will contain profile points when only points along a profile line were recorded. All eastings and northings are referenced to NAD83, State Plane Coordinates, Louisiana South Zone 17 in US Survey Feet. Elevations are displayed in US Survey Feet and are referenced to the datum shown on the indivdual survey drawing.
.SHP - ESRI Shapefile format; Digital vector storage format for storing geometric location and associated attribute information (Wikipedia). Zip files available contain data for project depth contour, shoaling polygons, and sounding points.