There is an "Inside Passage" for the Atlantic portion of the DelMarVa circumnavigation. It is actually an alternative route for the Intracoastal Waterway, which allows boats to bypass the Chesapeake and proceed straight up to Delaware Bay in protected waters along the east coast of the DelMarVa peninsula. Barrier beaches provide the protection, and the route wends its way through rivers and marshes, and across some inlet mouths.
The glitch is that it has many shallow spots (<4'), and charting is not perfectly reliable with shifting shoals etc, and there are some low bridges (mostly near the north end, but also a 40-footer at Cape Charles). So it is usually skipped by typical cruising sailboats.
I have gone around number of times in a shoal-draft boat, and we tend to go in and out. There are shallow parts where timing the tide is critical. There are few 35- and 40-foot bridges. Some parts are barely practical: Lewes to Indian River is very thin and even the smallest boats tend to go outside, and the Indian River Bridge is 35'; Indian River to Ocean City has a 5' bridge (!); OC to Chicoteague is fince except for a 35' bridge; Chincoteague has a reasonable chanel that is deep but mobile; Chincoteague to Wachapreague is rather thin and has a 35' bridge, and Watchapreague inlet is OK for shoal raft sailors in settled weather (big charter boats use it daily); Wahcapreage to Sand Shoal is quite thin, but I have done it twice, and sand shoal inlet is generally OK for shoa draft boats; Sand Shoal to Cape Charles is fine for shoal draft (done it twice) but there is a 40' bridge at the cape.
The reality is that larger boats stay out-side and stop at OC and Chincoteauge (trawlers drawing 12' use Chincoteague, with local knowledge - 6 feet is reasonable for visitors) if they choose. Smaller boats can run inside, according to their draft and the tide. They need to be careful with the weather, and NOT consider the inlets useable after the weather turns. You need to go inside while the weather is still fair.
The route does require navagation skill, attention to weather, a sense of adventure and a shoal draft (<3.5') boat, but I have done it 4x with a little girl for my crew. Great father-daughter times.
The biggest difference, behind the barrier islands, is the isolation. EVERYTHING between Cape Charles and Ocean City is either Nature Concervancy or park, and that makes it a very unique area. Not for those that like resorts, perfect for those who love nature.