This is an older movie that depicts all aboard go down with the ship and are found by some scientists. The people have been living in this sunken ship for several generations. When told that they can be rescued most of the older people decide to stay behind. This was a kind of sci-fi flick.

Goliath Awaits (http://www.imdb.com/title/tt0082461/)

That sounds like posidien adventure the original :o