There is no longer married housing available on campus and no pets are allowed because Mare Island is a wildlife refuge (they are afraid your cat might eat a bird).
Price range for off campus housing varies. I would say the average for off campus 2-BR apts is around $950-$1300 depending on neighborhood, commute distance, etc. Many students live in places like Benecia, Napa or Vacaville. Check the San Francisco Chronicle for Classified ads for these areas to get a better idea of pricing.
Rule of thumb: the closer you get to San Francisco the higher the rent. If you are willing to live 20 minutes from campus you will get better pricing in Fairfield or Vacaville but you will have to fight the commute traffic at times.