Columbus Day weekend is 7-9 Oct.
Sail Boat Show Week is followed by Power Boat Show Week. Hundreds of boats, thousands of exhibitors and Show-goers. Parking lots are full, as are accommodations for miles around. Many street parking spots are roped off for show support. Traffic oozes around downtown. Restaurant reservations are full. Locals stay away. You can see from the link below the scale, and the overhead shots show the hull-to-hull boats packing the harbor.
I live 6 miles from USNA, usually takes me 18 minutes to get to Gate 8. Boat Show, even going back way, can be 45 minutes. Forget Gate 1.
The Navy-Air Force football game is that weekend, so the USNA reunion classes for that game, and attending AF alum for an always-sold-out game, add in a x10 factor.
You could scoop him up after the game and head over to Ocean City or Rehoboth Beach for 2 nights, or stay in DC, or go into WV/VA/MD mountains for a getaway.
When we lived on the Yard, we would walk out to the Boat Shows and enjoyed it. As locals now, we avoid it.
If you go, and can't find a hotel near Annapolis, check the BWI airport hotel district, or Arundel Mills area, or Ft. Meade/Odenton area, all about 17-20 miles from Annapolis.