VHF Marine Radio Service

The Marine VHF radio is installed on all large ships and most motorized boats. It is used for a wide variety of purposes, including summoning rescue services and communicating with harbors and marinas and operates in the VHF frequency range, between 156 to 174 MHz.

A marine VHF set is a combined transmitter and receiver and only operates on standard, international frequencies known as channels. Channel 16 (156.8 MHz) is the international calling and distress channel. Channel 9 can also be used in some places as a secondary call and distress channel. Transmission power ranges between 1 and 25 watts, giving a maximum range of up to about 60 nautical miles between aerials mounted on tall ships and hills and 5 nautical miles between aerials mounted on small boats at sea level. (Frequency modulation is used).

Marine VHF mostly uses ‘simplex’ transmission, where communication can only take place in one direction at a time. A transmit button on the set or microphone determines whether it is operating as a transmitter or a receiver. The majority of channels, however, are set aside for ‘duplex’ transmissions channels where communication can take place in both directions simultaneously. Each duplex channel has two frequency assignments. This is mainly because, in the days before mobile phones became widespread, the duplex channels could be used to place calls on the public telephone system for a fee via a marine operator. This facility is still available in some areas, though its use has largely died out. In US waters, Marine VHF radios can also receive weather radio broadcasts, where they are available, on receive only channels.

Types of VHF Marine Equipment

Sets can be fixed or portable. A fixed set generally has the advantages of a more reliable power source, higher transmit power, a larger and more effective aerial and a bigger display and buttons. A portable set (often essentially a waterproof, VHF walkie-talkie in design) can be carried to a lifeboat in an emergency, has its own power source and is more easily water-proofed.

Marine radios can be ‘voice-only’ or can include ‘Digital Selective Calling‘.

Voice-only equipment is the traditional type, which relies totally on the human voice for calling and communicating.

A VHF set and a VHF channel 70 DSC set, the DSC on top, both produced by Sailor

Digital Selective Calling equipment, a part of GMDSS, provides all the functionality of voice-only equipment and, additionally, allows several other features:

• a transmitter can call a receiver automatically using Digital Selective Calling on Channel 70, using a telephone-type number known as a Maritime Mobile Service Identity or MMSI

• a distress button, which automatically sends a digital distress signal identifying the calling vessel and the nature of the emergency

• a connection to a GPS receiver allowing the digital distress message to contain the distressed vessel's position.

VHF Marine Radio Operating procedures

The accepted conventions for use of marine radio are collectively termed "proper operating procedure." These conventions include:

• Listening for 2 minutes before transmitting

• Using Channel 16 only to establish communication (if necessary) and then switch to a different channel

• using a set of international "calling" procedures such as the "Mayday" distress call, the "Pan-pan" urgency call and "Securité" navigational hazard call.

• using "pro-words" based on the English language such as Acknowledge, All after, All before, All stations, Confirm, Correct, Correction, In figures, In letters, Over, Out, Radio check, Read back, Received, Repeat, Say again, Spell, Standby, Station calling, This is, Wait, Word after, Word before, Wrong

• using the NATO phonetic alphabet: Alpha, Bravo, Charlie, Delta, Echo, Foxtrot, Golf, Hotel, India, Juliet, Kilo, Lima, Mike, November, Oscar, Papa, Quebec, Romeo, Sierra, Tango, Uniform, Victor, Whiskey, X-ray, Yankee, Zulu

• using a phonetic numbering system based on the English language: Wun, Too, Tree, Fow-er, Fife, Six, Sev-en, Ait, Nin-er, Zero, Decimal

Official VHF Marine Radio Channels

List of VHF Marine channels

Marine VHF Channels and Frequencies

Channel number	"A" frequency (MHz) Usually ship stations	"B" frequency (MHz) Usually coast stations	Notes
0	156.000	160.600	Private, coast guard
1	156.050	160.650
2	156.100	160.700
3	156.150	160.750
4	156.200	160.800
5	156.250	160.850
6	156.300	160.900	Ship-to-ship
7	156.350	160.950
8	156.400	161.000	Ship-to-ship
9	156.450	161.050	Ship-to-ship
10	156.500	161.100	Ship-to-ship
11	156.550	161.150
12	156.600	161.200
13	156.650	161.250	Ship-to-ship
14	156.700	161.300
15	156.750	161.350	Ship-to-ship
16	156.800	161.400	International distress, safety and calling Ⓐ
17	156.850	161.450	Ship-to-ship
18	156.900	161.500
19	156.950	161.550
20	157.000	161.600
21	157.050	161.650
22	157.100	161.700
23	157.150	161.750
24	157.200	161.800
25	157.250	161.850
26	157.300	161.900
27	157.350	161.950
28	157.400	162.000
60	156.025	160.625
61	156.075	160.675
62	156.125	160.725
63	156.175	160.775
64	156.225	160.825
65	156.275	160.875
66	156.325	160.925
67	156.375	160.975
68	156.425	161.275
69	156.475	161.075
70	156.525	161.125	Digital Selective Calling
71	156.575	161.175
72	156.625	161.225
73	156.675	161.275
74	156.725	161.325
75	156.775	161.375
76	156.825	161.425
77	156.875	161.475
78	156.925	161.525
79	156.975	161.575
80	157.275	161.625
81	157.075	161.675
82	157.125	161.725
83	157.175	161.775
84	157.225	161.825
85	157.275	161.875
86	157.325	161.925
87	157.375	161.975	Automatic Identification System
88	157.425	162.025	Automatic Identification System

 

VHF Marine Radio Rules The Official FCC Rules and Regulations for VHF Marine Radio Use

On October 25, 1996, the FCC released a Report and Order in WT Docket No. 96-82, 11 FCC Rcd 14849, FCC 96-421 eliminating the individual licensing requirement for voluntary ships operating domestically which are not required by law to carry a radio.

You do not need a license to operate a marine VHF radio, radar, or EPIRBs aboard voluntary ships operating domestically. The term "voluntary ships" refers to ships that are not required by law to carry a radio. Generally, this term applies to recreation or pleasure craft. The term "voluntary ships" does not apply to the following:

• Cargo ships over 300 gross tons navigating in the open sea;
• Ships certified by the U.S. Coast Guard to carry more than 6 passengers for hire in the open sea or tidewaters of the U.S.;
• Power driven ships over 20 meters in length on navigable waterways;
• Ships of more than 100 gross tons certified by the U.S. Coast Guard to carry at least one passenger on navigable waterways;
• Tow boats of more than 7.8 meters in length on navigable waterways; and,
• Uninspected commercial fishing industry vessels required to carry a VHF radio.
• Ships required to carry an Automatic Identification System (AIS) transceiver by the U.S. Coast Guard regulations enacted pursuant to the Maritime Transportation Security Act of 2000.
   

Global Maritime Distress and Safety System (GMDSS)

The FCC rules require certain vessels to be equipped with radio equipment for safety purposes. These rules are in accordance with international agreements. The GMDSS replaces the older 'Morse code' based safety system.

About Ship Radio Stations


A shipboard radio station includes all the transmitting and receiving equipment installed aboard a ship for communications afloat. Depending on the size, purpose, or destination of a ship, its radio station must meet certain requirements established by law or treaty. For example, large passenger or cargo ships that travel on the open sea are required by the Communications Act and by international agreements to be equipped with a radio station for long distance radio communications. Small passenger ships that travel along the coast may only need to communicate at shorter range with coast stations. These are examples of "compulsory ships" because they are required or compelled by treaty or statute to be equipped with specified telecommunications equipment.

Smaller ships used for recreation (e.g., sailing, diving, sport fishing, fishing, water skiing) are not required to have radio stations installed but they may be so equipped by choice. These ships are known as "voluntary ships" because they are not required by treaty or statute to carry a radio but voluntarily fit some of the same equipment used by compulsory ships.
Ship stations may communicate with other ship stations or coast stations primarily for safety, and secondarily for navigation and operational efficiency. The FCC regulates marine communications in cooperation with the U.S. Coast Guard, which monitors marine distress frequencies continuously to protect life and property. All users of marine radio, whether voluntary or compulsory, are responsible for observing both FCC and Coast Guard requirements.