Hong Kong, June 23 -- Submarines are the undisputed apex predator for navies around the world, and none have the range, endurance and payload capacity that nuclear-powered submarines do.

China is currently leading the world in terms of production of such lethal underwater weapons, and new ones are regularly wending their way into the People's Liberation Army Navy (PLAN).

Although Chinese submarines are cloaked in secrecy, a small part of the veil was recently lifted when satellite imagery revealed the existence of a mysterious new type at a berth in the fitting-out basin at Jiangnan Shipyard, Shanghai, on May 31. It is distinguished by the fact it does not have a sail, or what used to be called a "conning tower" in the old days.

The fi...