Funny you should ask.
I just put up a feed of some marine channels.
I have had the feed set up for a couple years for a local boating forum. I just put it on ScanAmerica yesterday.
Marine Scanner
It covers southern Lake Huron to north east Lake Erie including Lake St. Clair. I am scanning Coast Guard channels including Coast Guard helicopter and Selfridge Air National Guard tower. Sarnia Coast Guard can also be heard. It also scans several other marine channels including Sarnia Traffic freighter control. Sarnia Traffic gets turned off when the Coast Guard stuff gets busy.
It also scans Macomb County and St. Clair County Marine Sheriff.
I originally set it up for local boaters so it does scan the recreational traffic as well. Coast Guard channel 23 is set as the priority channel so when the helicopter is up the scanner won't miss communications.
I am located at the northern most part of Lake St. Clair right on the water. I have an Antennacraft ST2 37' in the air. I can pick up the helicopter up to a 50 - 60 mile radius.
If you follow the information link on ScanAmerica's page you will find some recordings of some of the stuff from this year. Nothing too exciting yet but interesting.
Here is a list of what I'm scanning.
156.3500 Marine Channel 7
156.4500 Marine Channel 9
156.5000 Mail Boat 10
156.5500 Sarnia Traffic 11
156.6000 Marine Channel 12
156.7000 Marine Channel 14
156.8000 Marine Channel 16
156.8500 Marine Channel 17
156.9000 Marine Channel 18
157.0000 Marine Channel 20
157.1000 Marine Channel 22
157.1500 CG Ops 23
157.2000 Marine Channel 24
156.4250 Marine Channel 68
156.4750 Marine Channel 69
156.5750 Marine Channel 71
156.6250 Marine Channel 72
156.6750 Marine Channel 73
156.7250 Marine Channel 74
156.9250 Marine Channel 78
157.0750 Marine Channel 81
157.1250 Marine Channel 82
161.8250 Marine Channel 84
156.9500 Marine Channel 19A
161.6000 Marine Channel 20B
157.0500 Marine Channel 21A
157.1750 CG Ops 83A
120.1500 SANG Tower