Tables on the following pages 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 Vessel Traffic System.
2. Alpha channel numbers, that is, channel numbers followed by the letter A (such as Channel 07A) 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 Canadian Coast Guards for handling distress and other calls. If your radio is set for international operation you will go to Channel 22 instead of 22A, and will not be able to communicate with the Coast Guard. To use Channel 22A, your radio must be set for USA or Canada operation. usually by a U/I/C (USA/International/Canada) control or combination of controls (see your Owner's Manual). Channel 22 (without an "A") is an International duplex channel for port operations. Some radios indicate an "A" adjacent to the alpha channels on the display; on others "alpha" is not indicated but the proper channel is selected based on the U/I/C setting.
3. Bridge-to-Bridge channels (for example, Channel 13) are for use by bridge operators on inter-coastal waterways and rivers. It is also used by marine vessels in the vicinity of these bridges for navigation and for communicating with the bridge operators. Note that a limit of 1 Watt is specified for these channels. See page 4 for additional information.
4. The SID column on the chart indicates either S (simplex) or D (duplex). Simplex means transmitting and receiving on the same frequency. It is obvious that 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 operation involves the use of one frequency for transmitting and a separate frequency 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 geographic regions. The Marine Radio-Telephone User's Handbook (see page 1) identifies shared channels in detail.
6. Marine vessels equipped with VHF radios are required to monitor Channel 16. For some radios, this is done automatically when the radio is on; see your Owner's Manual.
TABLE 1: CHANNELS 1 THRU 19
TABLE 2: CHANNELS 20 THRU 71
TABLE 3: CHANNELS 72 THRU WEATHER 10