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Maritime Telecommunications
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Services & Reporting:
Maritime Information:

Effective 01 August, 2013, the U. S. Coast Guard terminated its radio guard of the international voice distress, safety and calling frequency 2182 kHz and the international digital selective calling (DSC) distress and safety frequency 2187.5 kHz. Additionally, marine information and weather broadcasts transmitted on 2670 kHz will terminate concurrently. See the safety alert. Note that these frequencies are still available and in use, notwithstanding the Coast Guard's termination of the radio guard. Please contact us if you have any questions.


HF Simplex Channels

Exclusive Maritime Channels

These frequencies are shared and are not available for the exclusive use of any station.

4 MHz Band kHz 6 MHz Band kHz 8 MHz Band kHz 12 MHz Band kHz
4146 6224 8294 12,353
4149 6227 8297 12,356
4417 6230   12,359
  6516 (daytime only)   12,362
      12,365

4065,4089,4116,4408      

for Mississippi River 

6209,6212,6510,6513

for Mississippi River

8201,8213,8725,8737

for Mississippi River

12,362 12,365

for Mississippi River

  

16 MHz kHz 18/19 MHz Band kHz 22 MHz Band kHz 25/26 MHz Band kHz
16,528 18,825 22,159 25,100
16,531 18,828 22,162 25,103
16,534 18,831 22,165 25,106
16,537 18,834 22,168 25,109
16,540 18,837 22,171 25,112
16,543

for Mississippi River

18,840 22,174 25,115
16,546

for Mississippi River

18,843 22,177 25,118

Maritime Channels Shared with the Fixed Service

The following channels in the band 4000-4063 kHz and 8100-8195 kHz may be used:

  • for supplementing ship-to-shore channels for duplex operation;
  • for Intership simplex (single-frequency) and cross-band operation;
  • for cross-band working with coast stations;
  • for duplex operation with coast stations working in the band 4438-4650 kHz or with Channels 834, 835, 836 and 837;
  • for ship-to-shore or shore-to-ship simplex operations (8100-8195 kHz only).
Channel No. 4 MHz Carrier Frequency kHz 8 MHz Carrier Frequency kHz
1 4000 8101
2 4003 8104
3 4006 8107
4 4009 8110
5 4012 8113
6 4015 8116
7 4018 8119
8 4021 8122
9 4024 8125
10 4027 8128
11 4030 8131
12 4033 8134
13 4036 8137
14 4039 8140
15 4042 8143
16 4045 8146
17 4048 8149
18 4051 8152
19 4054 8155
20 4057 8158
21 4060 8161
22 -- 8164
23 -- 8167
24 -- 8170
25 -- 8173
26 -- 8176
27 -- 8179
28 -- 8182
29 -- 8185
30 -- 8188
31 -- 8191

Global Maritime Distress & Safety System DSC & Radiotelephone Channels

The simplex DSC frequencies are guarded and are used for digital alerting  and calling for distress, urgency and safety. Once the DSC call has been sent,  the corresponding radiotelephone frequency is used for voice communications.

These simplex voice frequencies are used for distress and safety communications, and (except for 2182 kHz) are not normally guarded.

DSC VOICE DSC VOICE
2187.5 2182 8414.5 8291
4207.5 4125 12,577 12,290
6312.0 6215 16,804.5 16,420