comdtinst m2400.1f - US Coast Guard Response Boat-Medium

Notes: # This is a shared Commercial-non-commercial Channel.
## Public Coorespondence Channels.
### This is a shared Commercial-non commercial Channel in the Great
Lakes.
Notes: VHF-FM Channels designated with an "A" (e.g. channel 22A) used in the
U.S. is the ship station transmit frequency portion of the
international channel. The coast stations transmit frequency portion
is not available to the maritime service in the U.S. As a result, all
channels designated with an "A" are not compatible with the
international duplex arrangement of the channel, and communication
with many foreign flag vessels (about 50%) on these channels are not
possible. Coast Guard units having this difficulty should ask the
foreign vessel to switch to another appropriate channel (e.g. 6) or
frequency (e.g. 2670 kHz).
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