great news, if true..
We lack in sub surface warfare and this should help a lot in future considering sub strength of chinese and porkis is also going to increase.
Double Hull are difficult to be sunk than single Hull, can be more quieter and carry more payload
But Double Hull face difficulty to submerge, heavy and can have range or drag issue.
Re: INS Vikramaditya (Adm Gorshkov) aircraft carrier
I believe india can ask us and russia to support or act as consultants in nuclear sub manufacture in india...