This 25-page report, published by Alexandria University, describes the design and construction of Neptune, an underwater remotely operated vehicle (ROV). This report was created by MIA Robotics, a student group that participated in the 2021 MATE ROV competitions Explorer 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 project and team. The design rationale is then presented, which includes information on the design evolution, mechanical design, electrical systems, software, and features. Testing and troubleshooting, challenges, lessons learned, areas for improvement, safe...