Notice to Navigators: Great Lakes Basin


LNM 40-21



This section contains information of general concern to the Mariners. Mariners are advised to use caution while transiting these areas.


DETROIT RIVER – MI – Trenton Channel – Chart 14853 - Hazard to Navigation

The Coast Guard has received a report of a 4-foot tall bolder in the navigation channel of the Grosse Isle Parkway Bridge (Free) at Mile 5.60, over the Detroit River, Trenton Channel. Mariners should use caution and report any information about the boulder to the nearest Coast Guard unit.


LAKE ST. CLAIR - MI - Dickinson Island, MI - Chart 14850 – Dredging

From 15 Oct to 15 Nov Luedtke Engineering Co. will be dredging the Channels in Lake St. Clair at the Eastern half of the Federal Channel and disposing of the material at the Dickinson Island disposal site 24 hours/7 days a week. The Tug Paul Luedtke and Tug Kurt Luedke will be transporting the scows and equipment. The Derrick Boat No. 16 will be barge completing the dredging in the East Outer Channel and can be contacted on VHF channels 10, 16, and 19. All mariners are requested to transit the area with caution.


LAKE MICHIGAN – WI – South Milwaukee – Chart 14924- Hazard to Navigation

The South Milwaukee Yacht Club will be secured for the season until spring 2022 due to the shoaling at the harbor entrance jetty, creating a hazard to navigation. Two-day boards are marking the entrance. All mariners are requested to transit the area with caution. For further questions, please contact Sector Lake Michigan at (414) 474-7182 or VIA VHF channel 16.