The following is from the CG 9th District Notice to Mariners 20/13.
The Cedar River Buoy 11 (LLNR 21794.4) and the Cedar River Buoy 12 (LLNR 21794.5) were unable to be commissioned due to low water depths. The channel is not wide enough to relocate the buoys without impeding navigation. All mariners use extreme caution when transiting the area. For further information contact Sector Lake Michigan at (414) 747-7182.