33 C.F.R. § 162.145
Monroe Harbor, Mich
(a) In the lake channel, no vessel greater than 40 feet in length may exceed 10 miles per hour.
(b) In the river channel:
(1) No vessel greater than 40 feet in length may exceed 6 miles per hour.
(2) No vessel may use a towline exceeding 200 feet in length.