Submarine operations are tightly held state secrets, so no wonder discerning fact from fiction regarding stories about them is daunting. The most recent case involves the apparent sinking of a new class of Chinese submarine—reportedly nuclear-powered.

The most remarkable element of this story isn’t the sinking. It’s the potential of China expanding the production of nuclear-powered submarines.

So, let’s recap what is being reported:

Earlier this year, naval experts tracking developments of China’s military noticed from satellite imagery a new class of submarine being built at Wuchang Shipyard, a yard in Wuhan known for constructing conventional submarines. Last Spring, satellite imagery detected barges and floating cranes at the new sub’s pier.

In late September, the Wall Street Journal reported that U.S. government sources confirmed a new class of nuclear-powered submarine had indeed sunk pier-side in Wuhan. As of October 8, there has not been an official statement made to corroborate this report. That said, it is highly unlikely a government source would leak such sensitive information without approval.

Yet some healthy skepticism is warranted.

A year ago, similar stories of a lost Chinese nuclear submarine were being reported. That case involved the loss in the Yellow Sea of a nuclear submarine ensnared by seafloor devices and corroborated by United Kingdom government sources. The details of that story never had compelling satellite imagery nor naval activity to corroborate the loss or even a recovery. As the story gained traction, eventually a Taiwan Ministry of Defense spokesman denied there was evidence to back up this story.

That said, the details of the 2023 story mirror an earlier incident. In 2003, Chinese fisherman spotted the periscope of a crippled Ming-class diesel submarine with all-hands dead from asphyxiation—likely due to improper operations while running diesel engines to recharge batteries.

So, yes, China does suffer submarine losses, and there have been some incidents in the recent past. Here, though, is why this latest story is different.

Firstly, satellite imagery corroborates a pier-side sinking of a new larger class of submarine with reputable reporting from government sources indicating it had a new nuclear power plant installed.

Secondly, China has been building Air Independent Propulsion (AIP) conventional submarines like the Yuan-class for years. Branching out into auxiliary nuclear power systems is logical and is not novel. In the 1980s, the Soviets attempted to use its VAU-6 nuclear power plant to extend its diesel submarines’ undersea endurance.

That China took inspiration from the Soviets is also not new, as their anti-ship ballistic missiles are in fact a Soviet invention. China naval expert Andrew Erickson at the China Maritime Studies Institutes points to 2017 public statements by a Chinese admiral further supporting this new boat being designed to incorporate nuclear power. News of expansion of facilities at the lone known Chinese nuclear submarine shipyard at Huludao in the Yellow Sea also supports the potential for installation of nuclear power systems on submarines produced at Wuchang.

The bottom line:

Clearly a new larger class of submarine was built by a shipyard known for building advanced Chinese conventional submarines. It is probable that this new boat sunk pier-side due to flooding either from a fouled hatch that could not be shut or improper shipyard work. The U.S. Navy had a similar experience in 1969 with the submarine Guitarro.

Moreover, given Chinese interest in and Soviet experience with auxiliary nuclear power systems on conventional submarines, the potential this new class of submarine is nuclear powered cannot be discounted. All told, skepticism is still called for until a fuller official accounting of this incident is made. But the potential that something else explains the size of this new class of submarine is still possible—perhaps, as some speculate, the construction of a new submarine vertical launch system.

But as noted earlier, the biggest take-away from this story is the potential expansion of China’s nuclear submarine production capacity. Longer submerged endurance, extended high speed range, and capacity to operate advanced sensors makes nuclear powered submarines the apex naval predator. China knows this and is seeking to expand its fleet of nuclear-powered submarines.