47 C.F.R. § 80.1077
The following table describes the frequencies used in the Global Maritime Distress and Safety System:
| Alerting: | |
| 406.0-406.1 EPIRBs | 406.0-406.1 MHz (Earth-to-space). 1544-1545 MHz (space-to-Earth). |
| INMARSAT Ship Earth Stations capable of voice and/or direct printing | 1626.5-1645.5 MHz (Earth-to-space). |
| VHF DSC Ch. 70 | 156.525 MHz.1 |
| MF/HF DSC2 | 2187.5 kHz3, 4207.5 kHz, 6312 kHz, 8414.5 kHz, 12577 kHz, and 16804.5 kHz. |
| On-scene communications: | |
| VHF Ch.16 | 156.8 MHz. |
| MF Radiotelephony | 2182 kHz. |
| NBDP | 2174.5 kHz. |
| Communications involving aircraft: | |
| On-scene, including search and rescue | 156.8 MHz4, 121.5 MHz5, 123.1 MHz, 156.3 MHz, 2182 kHz, 3023 kHz, 4125 kHz, and 5680 kHz.6 |
| Locating signals: | |
| 406-406.1 EPIRB Beacons | 121.5 MHz. |
| 9 GHz radar transponders | 9200-9500 MHz. |
| Maritime safety information (MSI): | |
| International NAVTEX | 518 kHz.7 |
| Warnings | 490 kHz, 4209.5 kHz. |
| NBDP | 4210 kHz, 6314 kHz, 8416.5 kHz, 12579 kHz, 16806.5 kHz, 19680.5 kHz, 22376 kHz, 26100.5 kHz. |
| Satellite | 1530-1545 MHz.10 |
| General distress and safety communications and calling: | |
| Satellite | 1530-1544 MHz (space-to-Earth) and 1626.5-1645.5 MHz (Earth-to-space).10 |
| Radiotelephony | 2182 kHz, 4125 kHz, 6215 kHz, 8291 kHz, 12290 kHz, 16420 kHz, and 156.8 MHz. |
| NBDP | 2174.5 kHz, 4177.5 kHz, 6268 kHz, 8376.5 kHz, 12520 kHz, and 16695 kHz. |
| DSC | 2187.5 kHz, 4207.5 kHz, 6312 kHz, 8414.5 kHz, 12577 kHz, 16804.5 kHz, and 156.525 MHz. |
| Survival craft: | |
| VHF radiotelephony | 156.8 MHz and one other 156-174 MHz frequency |
| 9 GHz radar transponders | 9200-9500 MHz. |
1 Frequency 156.525 MHz can be used for ship-to-ship alerting and, if within sea area A1, for ship-to-shore alerting.
2 For ships equipped with MF/HF equipment, there is a watch requirement on 2187.5 kHz, 8414.5 kHz, and one other frequency.
3 Frequency 2187.5 kHz can be used for ship-to-ship alerting and, if within sea area A2, for ship-to-shore alerting.
4 Frequency 156.8 MHz may also be used by aircraft for safety purposes only.
5 Frequency 121.5 MHz may be used by ships for aeronautical distress and urgency purposes.
6 The priority of use for ship-aircraft communications is 4125 kHz, then 3023 kHz. Additionally, frequencies 123.1 MHz, 3023 kHz and 5680 kHz can be used by land stations engaged in coordinated search and rescue operations.
7 The international NAVTEX frequency 518 kHz is the primary frequency for receiving maritime safety information. The other frequencies are used only to augment the coverage or information provided on 518 kHz.
8 [Reserved]
9 [Reserved]
10 In addition to EPIRBs, 1544-1545 MHz can be used for narrowband distress and safety operations and 1645.5-1646.5 MHz can be used for relay of distress alerts between satellites. Feeder links for satellite communications are assigned from the fixed satellite service, see 47 CFR § 2.106 .
11 [Reserved]
47 C.F.R. §80.1077