In the 1960s, American spy satellites scanning the Caspian Sea brought back pictures of something that should not have existed: a 100-metre, jet-powered hybrid of ship and aircraft, skimming the water at 500 km/h. The CIA called it the Caspian Sea Monster. The Soviets called it Korabl Maket. Then the USSR collapsed, the project rusted in port, and the world forgot.

This week, the Monster came back — with Mandarin instructions.

The clearest images yet of China’s “Bohai Sea Monster” just surfaced, and the analysts who track Chinese naval programmes are doing the maths. What Beijing has built is bigger than the Lun-class, more practical than the KM, and aimed squarely at the one military problem the United States has been pretending was solved: how to resupply a contested island in the western Pacific before anything that floats gets sunk.

A revival of the strangest idea in Cold War aviation

An ekranoplan is one of those concepts that sounds like a hoax until you see one move. Fly an aircraft within roughly one wingspan of a flat surface and a thick cushion of compressed air forms underneath, dramatically reducing induced drag. The result is a machine that’s heavier than any seaplane should be allowed to fly, faster than any ship has any right to move, and almost invisible to radar that’s looking for things in the air.

The Soviets ran with the concept harder than anyone. The KM “Caspian Sea Monster” first flew in 1966. The 286-tonne Lun-class — armed with six anti-ship cruise missiles — followed in 1987. They were fast, low, brutally efficient at sea level, and operationally nightmarish: they couldn’t climb out of ground effect, couldn’t fly in rough seas, and burned fuel like a furnace. When the USSR ran out of money, the programme died.

For four decades the design language sat in textbooks. Russia toyed with revivals. Iran built a much smaller version. The Americans funded the DARPA Liberty Lifter feasibility studies but never bent metal. Nobody actually built one at scale. Then this craft was photographed at a Chinese pier and the analyst community went sideways.

What the new images actually show

The latest photos reveal a four-engine craft with paired turboprop nacelles mounted above the wing, large multi-blade propellers, a stepped flying-boat hull, a tall joined V-tail, and outrigger pontoons at the wingtips for stability on the water. There’s a cockpit greenhouse in the nose. The fuselage is long, sleek, and clearly designed to carry cargo — not weapons.

That last detail is the clue. The Soviet Lun was a missile platform. The Bohai craft, by everything visible, is built for moving payload. Vehicles. Marines. Pallets. Fast.

Why China would actually want one of these

The problem with reinforcing an island in the South China Sea during a shooting war is that surface ships are slow and easy to find. Cargo aircraft are fast but can be intercepted by fighters. An ekranoplan is the awkward third option: it moves at 400–500 km/h, flies at 5–10 metres above the water (below most radar horizons), and can carry the kind of payload that needs a landing craft to deliver. If you’re Beijing, planning around a Taiwan-strait scenario, that triangle of speed-stealth-capacity is exactly the missing piece.

It also explains the deployment location. The Bohai Sea is a sheltered, shallow, military test bed adjacent to major shipyards. It’s where the Type 003 carrier was photographed for years before it sailed. China clearly wants this thing seen and understood — just not in operational detail.

The big unanswered question is how many. One craft is a curiosity. A squadron is a doctrine. The next set of satellite passes will tell us which.

Sources: The Aviationist, Naval News, The War Zone, Covert Shores (H I Sutton), Aerospace Global News, Defense Mirror.