GX1000S
Page 48
14 CHANNEL ASSIGNMENTS
Tables on the following columns list the VHF Marine Channel assignments for
U.S.A. and International use. Below are listed some data about the charts.
1. VTS. Where indicated, these channels are part of the U.S. Coast Guard’s
V
essel
T
raffic
S
ystem.
2. Alpha channel numbers, that is, channel numbers followed by the letter A
(such as Channel 07
A
) are
simplex
channels on the U.S.A. or Canadian
channel assignments whose counterparts in the International assignments
are
duplex
channels. International channels do not use “alpha” numbers.
If you call the Coast Guard on Channel 16, they will sometimes ask you to
“
go to channel 22 Alpha
.” This is a channel assigned to U.S.A, and Cana-
dian Coast Guards for handling distress and other calls. If your radio is set
for
International
operation you will go to Channel 22 instead of 22
A
, and
will not be able to communicate with the Coast Guard. To use Channel
22
A
, your radio must be set for
USA
or
Canada
operation, usually by a U/
I/C (USA/International/Canada) control or combination of controls. Chan-
nel 22 (without an “A”) is an
International
duplex channel for port opera-
tions. Some radios indicate an “A” adjacent to the alpha channels on the
display; on others “alpha” is not indicated but the proper channel is se-
lected based on the U/I/C setting.
3. Bridge-to-Bridge channels (for example, Channel 13) are for use by bridge
operators on intercoastal waterways and rivers. It is also used by marine
vessels in the vicinity of these bridges for navigation and for communicat-
ing with the bridge operators. Note that a limit of 1 Watt is specified for
these channels. See page 28 for additional information.
4. The
S/D
column on the chart indicates either S (simplex) or D (duplex).
Sim-
plex
means transmitting and receiving on the same frequency. Only one party
at a time can talk, unlike a telephone. Be sure to say “
over
” and release your
microphone push-to-talk switch at the end of each transmission.
Duplex
op-
eration involves the use of one frequency for transmitting and a separate fre-
quency for receiving. On channels specified as duplex on the charts, correct
mode of operation is established automatically by your radio when you select a
channel; you cannot change the mode. And you still must release the push-to-
talk switch after each transmission in order to listen to the radio.
5. Channels normally used by recreational boaters are those that include the
term “non-commercial” in the
Channel Use
column of the chart. Some of
these are shared with other users and some are used only in certain geo-
graphic regions.
6. Marine vessels equipped with VHF radios are required to monitor Channel 16.
