During the Cold War, both superpowers tried to weaponize the ocean's surface itself. The US Navy's answer was jet-powered seaplanes, the Martin P6M Sea Master and the supersonic Convair F2Y Sea Dart, built to hide nuclear strike capability from satellite surveillance by operating off open water instead of fixed runways. The film traces their declassified test programs, including the crashes that helped kill both projects, through archival footage and historian narration. On the Soviet side, engineers pursued an entirely different solution: the ground-effect Ekranoplan, a hybrid aircraft-ship that skims meters above the waves, culminating in the enormous prototype nicknamed the Caspian Sea Monster. The documentary lays out why each nation chased a different technical bet to solve the same strategic problem, how satellite reconnaissance eventually made the whole approach obsolete, and why these machines disappeared from military planning despite decades of investment. Declassified documents and period footage carry most of the story, with the test pilots' and engineers' setbacks given as much attention as the aircraft's capabilities.