HATTERAS, N.C. (AP) — Ferry runs between Hatteras and Ocracoke Island are being adjusted to help with an emergency dredging effort.

A news release from the N.C. Department of Transportation says there are concerns about shoaling at the northern end of Ocracoke Island. The adjusted schedules take effect Friday and will continue until dredging is complete.

Ferries will leave Hatteras on the hour from 5 a.m. until 6 p.m., then again at 7:30 p.m., 9 p.m., 10 p.m. and midnight.

From Ocracoke, ferries will leave initially at 4:30 a.m., then at 6:30 a.m. and every hour on the half-hour through 5:30 p.m. The remaining runs from Ocracoke are scheduled for 6:15 p.m., 7:30 p.m., 8:45 p.m., 10:30 p.m. and midnight.

NCDOT said two "shuttle" ferries will make unscheduled departures during peak periods.