This document summarizes the HEALY 1202 cruise report. The cruise took place from August 25 to September 27, 2012, mapping the US Arctic Ocean margin to support claims to an extended continental shelf under international law. Previous HEALY cruises since 2003 had similarly mapped the region. This cruise mapped over 29,000 km2 of seafloor using multibeam sonar and collected other geophysical data. The data helps define the outer limits of the US continental shelf and sediment thickness as required by the UN Convention on the Law of the Sea.