Definitely put in the Coast Guard channels and also, VTS Sarnia if you don't already have them programmed.
156.550 - Sarnia traffic (ch.11) from Huron Cut to St.Clair Crib Light.
156.600 - Sarnia traffic (ch.12) from Detroit River Light to St. Clair Crib.
156.650 - Sarnia traffic (ch.13) back up for ch. 11 + 12
With the recent Ice jam there were a lot of bridge to bridge comm's between Ice Breakers and ships in ice convoys. The Ice Breakers also checked in with Sarnia traffic frequently. At night they suspended activities for safety, hope this helps out, it was very active listening a couple weeks ago, and all in the clear.