From the Ninth-District weekly notice to mariners:
"The U. S. Coast Guard will be changing the radio frequency to turn on radio-controlled fog signals to channel 83A (157.175 MHz) by 01 July 2012.
"During this transition period, mariners should use both channel 79 (156.975 MHz) and channel 83A (157.175 MHz) to energize the fog signal."
Notice that it's VHF channel 83A, not 83B, which is the Canadian weather channel.
Fleet Captain, GLCC