The new type is estimated to be 35m long and 4m across. Although there are several possible explanations, the most likely role in my view is as a dedicated Special Forces submarine loosely equivalent to the Cos.Mo.S MG110, Crocodile-250 ("HERE") and Darkon-220 ("HERE"). It is also about the same length as the North Korean Sang-O class and comparisons are inevitable, but the likeness is likely to be weak. Today China is capable of producing a first-tier design in this class and shouldn't be underrated.

The submarine was spotted in Google Earth imagery outside the Wuchang shipyard (Wuchang Shipbuilding Industry Co., Ltd http://www.wuchuan.com.cn/) where several classes of warships and modern diesel-electric submarines are produced.

Other possible roles include:
a) Small dedicated test and evaluation submarine - it would be cheaper to build than a larger boat. However, it would also be less flexible and China has ample submarines for modifications and trials.
b) A special purpose / ocean engineering spy submarine similar to the US Navy's famous NR-1. However, the choice of shipyard suggests that it is not nuclear powered so its suitability for that type of mission is very limited.
c) Small inshore attack submarine. However, China has no need to build such small boats fo this mission wth ample full-size attack boats in service.
d) Training submarine similar to USS Mackerel
e) An export type
f) A dedicated ASW target