North Carolina Ferry System officials said nearly 900 vehicles and almost 2,000 people used the boats to leave Ocracoke Island on Monday after the mandatory evacuation of visitors.
Resident evacuations began Tuesday.
Minor ocean overwash was reported on the north end of Ocracoke Island at high tide Tuesday morning, and officials said it will only get worse during high tides through Friday.
They added that there is a very real probability that NC12 will be closed, quite possibly for several days.