These data are bathymetry (lake bottom elevation) in XYZ format, generated from the April 9-10, 2018, survey of Bourbon Lake and Williams Lake near Loretto, Kentucky. Bathymetric and topographic data were collected using an autonomous underwater vehicle (AUV) and a real-time kinematic global positioning system (GPS). Data were collected as the AUV traversed the lake along planned survey lines, and these data were supplemented by manual GPS shots in a few areas the AUV could not reach. Data collection software integrated and stored the depth and position data from the AUV in real time. Data processing required computer software to extract bathymetry data from the raw data files and to summarize and map the information.