China will send 20 electric trains to Latin America, and one metro system could become the region\u2019s longest\u00a0<\/a><\/h4>\n<\/div>\n<\/div><\/div>\n<\/div>\n\n\n\nSo why remove it? The main answer appears to be water itself. A sail creates drag, and drag means resistance, noise, and lost efficiency when a submarine is trying to move quietly through the sea.<\/p>\n\n\n\n
That matters because underwater warfare is a game of hide-and-seek where sound often decides who survives. The War Zone (TWZ) notes that deleting a large structure from the top of the hull can improve streamlining, speed, maneuverability, and quietness while submerged. Quieter means harder to detect.<\/p>\n\n\n\n
The tradeoff<\/h2>\n\n\n\n
There is a catch, of course. The sail is not just a decorative bump on the hull. It normally supports periscopes, communications antennas, snorkels, sensor masts, and other equipment that submarines need during certain operations.<\/p>\n\n\n\n
Take that structure away, and engineers have to solve a long list of problems somewhere else. Surface navigation becomes more complicated, awareness around the boat may be reduced, and polar operations can become harder because hardened sails can help break through ice.<\/p>\n\n\n\n
That is why this design feels important. China may be deciding that the underwater benefits are worth the sacrifice, or that newer sensors and mast systems can replace enough of what the sail used to do. Either way, the old rulebook is being tested.<\/p>\n\n\n\n
Years of quiet testing<\/h2>\n\n\n\n
This did not come out of nowhere. The same JN Shipyard in Shanghai launched a much smaller low-profile submarine in 2018, estimated by analyst H.I. Sutton at about 150 ft. long. That earlier boat may have served as a technology demonstrator for the same broad design idea.<\/p>\n\n\n\n
The new vessel appears to be a much bigger step. Moving from a 150-ft. testbed to something close to 394 ft. long suggests that China has been working through this concept for years, not just sketching futuristic shapes on paper.<\/p>\n\n\n\n
Satellite imagery also indicates features that fit the same stealth-focused logic. Analysts have pointed to X-form rudders and a possible shrouded propulsor, which could be a pumpjet type. Both would make sense for a boat designed around underwater efficiency and lower acoustic signature.<\/p>\n\n\n\n
The drone link<\/h2>\n\n\n\n
The design also echoes a wider push into uncrewed underwater systems<\/a>. In 2024, the state-run China State Shipbuilding Corporation showed off a large diesel-electric uncrewed underwater vehicle concept with a similar low-profile shape.<\/p>\n\n\n\nIts proposed missions included attacking ships, laying mines, supporting special operations forces, and serving as a mothership for smaller underwater drones.<\/p>\n\n\n\n
That does not mean this new submarine is a giant drone. TWZ notes that the boat seems unlikely to be fully uncrewed, given its size and uncertain role. But the resemblance matters because it hints at a design family built around stealth, endurance, and operations deep in contested waters.<\/p>\n\n\n\n