Shallowbag Bay is essentially Manteo Harbor. While less than 5 feet in many spots, there are good anchorages as Brian points out. The channels into Shallowbag Bay are narrow and require vigilance as Claiborne warns with these comments:
“A word of caution, one of the two approaches for vessels northbound on Pamlico Sound, and the far shorter of the two, is by way of the Old House Channel from the Pamlico, to southern Roanoke Sound, and then north on the Roanoke Sound channel. There is NOTHING easy about this passage, and I do not recommend it for vessels drawing 5 feet or more.
The other, far deeper and navigationally easier route is by way of Croatoan Sound, and then a southerly cruise through northern Roanoke Sound. The caveat for this route is that you must pass under a fixed bridge with 45 feet of vertical clearance, plenty for almost all powercraft, but not enough for many sailboats. The safest and easiest route to Manteo is by way of the AICW to Albemarle Sound. Then, a turn to the east will lead to northern Roanoke Sound, and then a quick trip to Shallowbag Bay and Manteo. However, you get there, Manteo is worth the effort!”
Claiborne

I have gained great knowledge in reading others posts on this site and thought it was time to return the favor. On August 12, 2010, we visited Manteo, NC aboard Tranquility. Tranquility has a tall mast and 6′ draft. We had no problem entering Shallowbag Bay and anchoring just east of the charted sewer outflow. Holding was good as a pretty severe thunderstorm rolled through with 30 mph gusts.
Captain Brian Campbell

Click on the Chartlet Below for a Chart View Window for Shallowbag Bay.