A hugely significant weakness and set-back for the Chinese Navy and particularly its submarine capability was featured in recent Nikkei analysis, which found that its coastal system already has geography working against it, while at the same time giving Japan and Taiwan a significant edge.
"When you look at China’s submarine bases, every single one of them has a fair bit of shallow water that their submarines have to transit through in order to get to deep water," former US Navy submariner Tom Shugart explained to Nikkei Asia.
A key issue is that submarines are much easier for rival nations to search out and track as they traverse shallow water, while in deep sea waters identity and defensive action against subs becomes extremely difficult.
What's more is that US allies Japan and Taiwan are much less constrained by these "chokepoints" which are more characteristic of China's shallower coastal waters. This gives the Japanese and Taiwanese navies the ability to deep dive a submarine fast, and quickly drop off their east coasts.
"A fast take a look at Google Earth reveals that China’s coast is surrounded by mild blue — which displays shallow seas— in distinction to the darkish blue deep waters that instantly drop off from the east coasts of Taiwan and Japan," Nikkei observes.