I have not been to this museum. I suspect there is not much visitorship so interest in expanding the museum is poor. For me, a trip to Annapolis for the Navy museum and experience is the place to be.
http://www.usna.edu/NAFPRODV/VC/
See the crypt of John Paul Jones. The most ornate casket you will ever see.
http://uss-rangerguy.com/john_paul_jones_crypt.htm
This is probably you best bet on navy history. If you want modern....go to the Norfolk VA.
http://www.hrnm.navy.mil/
DC is not always the best place for some things. However, the museums on the mall are fantastic and the price is great....free! The Hazy museum in VA for aircraft is simply the best out there IMO.