It doesn't have to say underwater for 25 years its just what it can do. Having a submarine that has the capability to stay underwater for 25 years is a nice luxury to have just in case if it was needed, but that doesn't mean that some people will be down there for a total of 25 years. Get it through your head stupid!!!
The United States should invest millions on as many subs as possible that can stay under water for 25 years or more because the utility of this capability cannot be understated. In fact, once testing is complete its first group of sailors should be the leadership of National Organization of Women.
With today's technology, there is no need to have a submarine where people can live underwater for that period of time. Instead, the government should spend its money thinking about more important things. There are other things we can develop that do a better job keeping the country safe from outside threats.
No, it would be a miserable life staying underwater for 25 years. What purpose would such a craft serve? Why does something need to remain stealth for so long? I feel the people aboard a submarine that doesn't surface for 25 years would go crazy. They would miss out on so much of life. It's not worth it.
I believe the purpose of this project is that this submarine can stay underwater for 25 years, in the event of a nuclear war. If we do have a nuclear war at some point, it will be such a catastrophe that I doubt 25 years would be long enough to remain underwater. It would be very expensive and what would be gained is very questionable.