Decades after the Soviet Union’s ambitious ekranoplan project faded, a new wave of interest in these unique ground-effect vehicles is emerging, with China reportedly testing a prototype and the United States recently exploring similar concepts.
During the Cold War, the CIA observed a mysterious craft dubbed the “Caspian Sea Monster” under construction in the Soviet Union. This ekranoplan was a military vessel designed to skim across water at speeds comparable to fighter jets, leveraging the aerodynamic principle of ground effect.
China’s “Bohai Sea Monster” and Strategic Ambitions
Recent photographs from China suggest Beijing may be constructing a similar vehicle in the Bohai Sea, promptly named the “Bohai Sea Monster.” Military aviation expert Justin Bronk of the Royal United Services Institute told Radio Free Europe that China’s experimental craft highlights its willingness to explore almost any technological solution for tactical advantages over rivals.
“China is known for its determination to fund and test a multitude of different technical and technological solutions to military problems,” Bronk stated, adding that Beijing is even trying designs with a low probability of success, “perhaps based on the logic that some, at least, will prove useful and successful.”
While there is no concrete evidence of the Bohai Sea craft’s military purpose, its gray color and large cargo bay lead experts to speculate it could be a military logistical vessel. Bronk suggests it could enable the Chinese navy to transport “cargoes that are too heavy even for large military transport aircraft, faster than traditional ships.” Such a vessel could also allow China to “reinforce small disputed islands more quickly with significant anti-ship and anti-aircraft systems.”
Ekranoplan Advantages and Past Challenges
Ekranoplans offer several distinct advantages:
- Low Observability: Flying just above the surface, they remain hidden from most radar systems until they appear over the horizon.
- High Speed: With speeds up to 10 times greater than traditional warships, an approaching ekranoplan fleet would offer coastal defenses little reaction time.
- Mine Resistance: They can pass over anti-ship mines unharmed.
- Increased Payload: They can carry larger loads than aircraft of comparable size.
However, historical ekranoplan designs faced challenges, primarily the high power required for takeoff, which could offset the fuel efficiency gained from low-altitude flight. Additionally, flying just above sea level exposes the vehicles to a higher risk of bird strikes compared to high-altitude aircraft.
US “Liberty Lifter” Program and Geopolitical Context
These advantages recently captured the imagination of engineers at the U.S. Defense Advanced Research Projects Agency (DARPA), which reportedly spent $22 million designing models for a flying ship called the “Liberty Lifter.” However, the U.S. program was prematurely halted in June 2025. A spokesperson for one of the involved companies indicated the program successfully demonstrated “design stability and the feasibility of new manufacturing techniques,” but no further visible progress has been reported beyond design sketches.
In contrast, the leaked images from China suggest Beijing has reached the prototype testing phase for its flying-sailing vehicle. This development comes as China’s navy rapidly expands, reportedly aiming to build a fleet of six aircraft carriers by the 2030s. The recent sightings of unusual craft have heightened concerns that Beijing is actively preparing for a potential invasion of Taiwan.
