This 23-page report, published by Boulder High School, describes the design and construction of Hammerhead, an underwater remotely operated vehicle (ROV) meant to assist in remediating "plastic pollution, the loss of coral reefs, and the contamination of waterways." This report was created by the Robosharks, a student group that participated in the 2021 MATE ROV competitions Ranger class. MATE ROV is a global underwater robotics competition for STEM students. The competition includes Explorer, Ranger, Navigator, and Scout classes.In the report, an abstract introduces the ROV and report. The report then considers the design rationale. This includes information on mechanical elements, propulsion, m...