I think it's utter absurd for a number reasons but I digress.Now, am i the only one who thinks a starship underwater slowly ascending is damn cool!?
1, You may think it's absurd, but following the history, logic and science of all (canon) Trek, it is possible.
2, JJ (and Paramount, et al) need (again) to make a Trek movie that will bring in the movie going audience (not just the Trek audience) to keep making more. IF every so called Trek fan didn't go to this movie and every other movie going person did (because they see this as an action/adventure/sci-fi/fun film), the movie would be a blockbuster. It's lucky that they do keep Trek alive. In this time, you have to update to be a viable franchise, something B&B did not understand in Voyager and Enterprise. It was the same thing.