This report was prepared as part of a multiyear project funded by the U.S. Nuclear Regulatory Commission to study potential effects of tsunamis produced from marine landslides. We thank the captains and crews of the National Oceanic and Atmospheric Administration Ship Okeanos Explorer and the research vessel Marcus G. Langseth for their recent mapping efforts along the Atlantic margin. Deborah Hutchinson and Nathan Miller of the U.S. Geological Survey (USGS) provided helpful comments. We thank VeeAnn Cross of the USGS for her comments on the metadata, Andrea Toran for her expertise in Web design, and Jonas Casey-Williams for his editorial review of this report.