I am trying to identify areas of interest in the ocean around 30-150 m that have some "topographic relief" compared to their surrounding areas. I did this manually by looking at the hillshade and circling areas that look like they "bulge out" a little big. However, I know this is not that advanced and was wondering if there was an automated method for detecting relief and creating new polygons from this detection. Thank you so much. Please respond by keeping in mind I am a beginner.