I read something about this-the area proposed would block entrance to the Norfolk, Hampton Roads, and Newport News shipyards..
I can't get to the article for some reason but the only way to block off the entrance to Chesapeake Bay with oil rigs is to do it intentionally-in other words, it's a B.S. reason.
Maybe the Navy is looking for a quid pro quid with Virginia Beach. VB supports keeping NAS Oceana, Navy won't support oil rigs.