If you go through on a weekend, especially a Sunday, you are extremely unlikely to encounter US Navy vessels underway around Norfolk. Unlike when I was in the Navy, ALL US Naval vessels underway in harbors and bays have short range weapons manned and ready. The officer-of-the deck on passing Navy ships will have you under the watchful eye of a gun crew, but no weapon will be pointed at you unless you disobey the rules which are:
The basic guidelines are as follows:
Vessels within 500 yards of a U.S. naval vessel must operate at the minimum speed necessary to maintain a safe course and proceed as directed by the official patrol.
Recreational and commercial vessels are not allowed within 100 yards of a U.S. naval vessel, unless authorized by the official patrol.
Vessels requesting to pass within 100 yards of a U.S. naval vessel must contact the official patrol on VHF-FM channel 16. The official patrol may permit vessels that can operate safely only in a navigable channel to pass within 100 yards of a U.S. naval vessel in order to ensure a safe passage in accordance with the Navigation Rules.
Commercial vessels anchored in a designated anchorage area may be permitted to remain at anchor within 100 yards of passing naval vessels.
Mariners who violate a Naval Vessel Protection Zone will be perceived as a threat, and will face a quick, determined, and severe response. Violators are subject to arrest, prosecution, and, if convicted, imprisonment for up to six years and a fine of up to $250,000.
The subs, as mentioned, are escorted by gray US Navy escort boats flashing blue lights, but the other ships are not, at least not last March when I went through. There may be a USCG vessel leading the sub too. You will have no trouble with them as long as you do not turn toward them or increase speed. Minding your own business outside the marked channel, as recommended before, is going to see you through just fine.
There are no other areas of particular note to be concerned about, and your normal safe navigation practices with a chartplotter will be sufficient just as anywhere else you may go. As said before, enjoy the diversity of the area and DO NOT worry.