My VHF radio, like most modern sets, has scanning capability. I can pick a set of channels to be scanned. While I am out daysailing from Fairport I typically scan 16 and all of the Coast Guard working channels. I hear all of the CG communications. When they are engaged in operations I hear about it. When they bring in the helicopter from Detroit for search and rescue I hear the comms between the surface craft and the helo. If you want to hear it all, program your VHF radio to scan these channels: 16, 21, 22, 23, 81, and 83. Just remember to take you radio off scan and pick a none USCG channel when you make a call.
The USCG also has some operational frequencies that are not marine VHF. If you have a programmable scanner you might be able to hear your local Coast Guard on some of these (MHz):
162.02 164.9125 162.125 164.9875 162.225 165.2125 162.25 165.3125 162.325 165.5625 162.5625 171.2375 163.125 171.3125 163.175 171.3375 163.4375 171.3625 164.3 381.7 164.55 381.8 164.775USCG Auxiliary officers who are also ham radio operators have been known to use 143.28 and 143.875 MHz.
The following are VHF search and rescue (SAR) frequencies that are used when there is a missing or sinking vessel (MHz):
123.1 149.5375 156.3 (VHF CH6) 282.8 383.9 156.6 (VHF CH12)
The following frequencies are for shipboard simplex or repeater use on commercial vessels:
457.525 457.55 457.575 457.60
Click here for a table of VHF channels
Click here for maps of Fairport
USCG web site