33 CFR § 110.206 - Detroit River, Michigan.
(a) The Anchorage grounds. Belle Isle Anchorage. The area is in the Detroit River immediately downstream from Belle Isle on the U.S. side of the International Boundary line within the following boundaries: beginning at a point bearing 250 T, 5400 feet from the James Scott Memorial Fountain (42°20′06″ N., 82°59′57″ W.) at the West end of Belle Isle; then 251 T, 3000 feet; thence 341 T, 800 feet; thence 071 T, 3000 feet; thence 161 T, 800 feet to the point of beginning.
(b) The regulations.
(1) Vessels shall be anchored so as not to swing into the channel or across steering courses.
(2) The Belle Isle Anchorage area is for the temporary use of vessels of all types, but especially for naval and merchant vessels awaiting berths, weather, or other conditions favorable to the resumptions of their voyage.
(3) No vessel may be anchored unless it maintains a continuous bridge watch, guards and answers channel 16 FM and channel 12 FM (VTC SARNIA sector frequency), maintains an accurate position plot and can take appropriate action to ensure the safety of the vessel, structures and other vessels.
(4) Vessels may not anchor in the Belle Isle Anchorage for more than 72 hours without permission of the Captain of the Port of Detroit.