Long-term underwater surveillance projects are where the Hydro Sentinel MK-IV shines. Its sophisticated power system runs continuously for up to 45 days without resuracing using hydrogen fuel cells. Stealth features of the platform include sound dampening technologies and a biomimetic façade evocative of local marine life. Improved with several high-resolution sensors and sophisticated image processing techniques, the Sentinel can run in low-light environments and murky waterways.