VHF Radio 101 - What you need to know before buying one?

VHF Radio 101

Just like other marine radios, a VHF marine radio is designed to enable reliable communication while boating. VHF radios function both from vessel to vessel and ship to shore although they are not used on shore. They’re also used for harbour calls and search & rescue operations.

Each VHF radio comes with its own receiver and transmitter which operates on a certain region specifically allowed by the device. “VHF” or very high frequency pertains to the frequency range between 156.0 to 174 MHz. VHF marine radios while not required by law (on personal craft) are an essential piece of your safety equipment.

There are two types of VHF marine radios - handheld marine radios which are used in smaller boats and as backup VHF radios on larger boats and fixed mount marine radios which are larger and more powerful.

Where are VHF Marine Radios used?

Technically, all sea vessels should have a VHF marine radio. It doesn’t matter if you’re riding a small fishing boat, yacht, or even larger ship -- VHF marine radios are safety tools that should be installed on all sea vessels including boats crossing large rivers, lakes or other navigable waterways. 

A almost all VHF Marine radios can work as both a receiver and a transmitter. It will operate using standard international frequencies or what is often referred to as “channels”. Today, modern VHF marine radios have loads of extra functions like DSC capability, channel scan, weather and waterproof tech that make the device more durable and useful.

VHF Radio Features:

Fixed or Handheld VHF radios have a variety of special features. Here are some of the most common VHF radio features:

  • Weather Alert - notifies users when the device detects a special weather warning signal from the NOAA. It can warn you about tornados, thunderstorms and other life-threatening weather conditions.
  • Waterproof - your radio will still function even if dropped in the water. There are several different water proof ratings.
  • Float ‘N Flash - This feature allows your VHF marine radio to float and flash a light when dropped in the water. This works even if your radio is turned off making it easier to retrieve devices accidentally thrown or dropeed off the boat. (See a list of the VHF radios with this feature here)
  • DSC (Digital Selective Calling) - used to send distress alerts with a simple press of a button. Once your radio is registered with OFCOM, you can receive an MMSI number that sends and receive information on a specific channel. Read how to make a Distress Call.
  • Loud Audio - Powerful audio output which can produce quality sound even if surrounded by other noises.
  • USB Charging - Easy charging which makes marine radios compatible with most USB cables or mobile batteries.
  • Dual/Tri Watch - This feature enables you to keep monitoring channel 16 whilst being able to scan other channels.
  • Tag Scan - feature that allows devices to remember specific channels to monitor.
  • ATIS Programmable - Enables you to cross international waters with contact to channels from that part of the world.
  • Noise-canceling technology- helps the device reduce background noise so that transmissions are loud and clear.
  • AquaQuake tech - drains water from the device’s speaker so that audio is clearer even during stormy situations.

How To Make a Distress Call:

A distress call or what they call a mayday call can indicate a serious life or property risk at sea. Nobody wants to be doing this BUT it’s crucial for everyone to learn how to do it. Boating emergencies and accidents can happen anywhere and at anytime. Engine trouble… super storms… and medical emergencies happen everyday on the water. By knowing how to make a distress call, you can better handle emergencies when they arise.

When a vessel issues a distress call on Channel 16, the caller has to follow a protocol in order to be understood and rescued as quickly as possible. Distress calls are constantly being monitored by the U.S coast guard so if you have a VHF radio on your boat, you can easily be rescued should an emergecy arise. 

DSC distress calls can be automatically sent with a simple push of a button. Once the distress call is sent, the coast guard and all other DSC radio-equipped vessels will be alerted. They will know the name of your vessel and location. Once received, the coast guard will respond automatically through Channel 16 for voice communication.

When your distress call is answered, you have to respond with the following details:

  • Name of Your Boat/Ship/Vessel : This is ______
  • Your Latitude and Longitude (Location) : We are at ________
  • Your Problem : We are experiencing _______ (ex.sinking, fire, medical emergency)
  • Number of People on Board : We currently have _______ people onboard, over.

There are penalties for the misuse of distress calls so do not use the emergency channel for any other purpose than a life-threatening emergency!

VHF Radio range:

VHF range can depend on a lot of factors. Usually, the range is determined by the position and length of the antenna. However, it’s worth noting that despite having a very high frequency and being less subject to atmospheric interference, VHF marine radios have a relatively short range. A handheld VHF can put out around 5 watts of power while a fixed VHF can put out up to 25 watts.

Essentially, VHF’s are “line of sight radios” which means your antenna needs to see the antenna of the other vessel in order to establish communications.

Topographical interventions like mountains can also affect transmission. So, in order to better communicate, consider adjusting your vessel’s antenna height. The higher you can place your VHGF antenna, the better you can communicate.

NOAA Marine Weather:

NOAA (National Oceanic and Atmospheric Administration) is responsible for operating the country’s environmental satellites. NOAA’s national weather service includes the use of service satellites and polar orbiting satellites to predict marine weather.

NOAA’s weather satellites are composed of two main types of satellites. The first one going by the acronym (GOES) or Geostationary Operational Environmental Satellite is used for short-range weather warnings while the second one, the Polar orbiting satellites are used for long-range forecasting.

  • GOES Satellites - continuously monitors the weather for intensive data analysis. It uses spacecraft and ground-based devices that work together and provide a stream of environmental data. They can forecast weather, track storms, and provide data for meteorology research. This satellite circles the earth in a “geosynchronous orbit” that matches the speed of the Earth’s rotation. It’s able to map the sea movements and lake ice, whilst also being able to detect ice fields. In addition, it can provide infrared radiometer data, temperature profiles, and radiation measurements. It can also be used to estimate snow accumulation, snow coverage, and rainfall amount.
  • Polar Orbiting Satellites - These satellites travel altitudes at different speeds. Basically, they can become “sun-synchronous” depending on the inclinations, orbital altitudes, and angular velocities of the planet. Compared to GOES satellites, polar-orbiting satellites can cover much area of our planet. However, unlike GOES satellites, Polar Orbiting Satellites can’t measure regions as continuously and as frequently as GOES. Polar orbiting satellites are frequently used by the US Air Force surveillance satellites.

VHF Channels and Radio Frequencies:

Owning a boating vessel comes with responsibilities including learning safety precautions. To ensure safety while on local and international waters, various systems exist to provide search and rescue assistance or communications to ships in their region. Having knowledge on how these systems work will help save you in times of distress.

Note: This is the Official copy of USA VHF Channels as reported on Navigation Center (United States Coast Guard)

New Channel Number

Old Channel Number

Ship Transmit MHz

Ship Receive MHz

Use

1001

01A

156.050

156.050

Port Operations and Commercial, VTS. Available only in New Orleans / Lower Mississippi area.

1005

05A

156.250

156.250

Port Operations or VTS in the Houston, New Orleans and Seattle areas.

06

06

156.300

156.300

Intership Safety

1007

07A

156.350

156.350

Commercial. VDSMS

08

08

156.400

156.400

Commercial (Intership only). VDSMS

09

09

156.450

156.450

Boater Calling. Commercial and Non-Commercial. VDSMS

10

10

156.500

156.500

Commercial. VDSMS

11

11

156.550

156.550

Commercial. VTS in selected areas. VDSMS

12

12

156.600

156.600

Port Operations. VTS in selected areas.

13

13

156.650

156.650

Intership Navigation Safety (Bridge-to-bridge). Ships >20m length maintain a listening watch on this channel in US waters.

14

14

156.700

156.700

Port Operations. VTS in selected areas.

15

15

156.750

Environmental (Receive only). Used by Class C EPIRBs.

16

16

156.800

156.800

International Distress, Safety and Calling. Ships required to carry radio, USCG, and most coast stations maintain a listening watch on this channel.

17

17

156.850

156.850

State & local govt maritime control

1018

18A

156.900

156.900

Commercial. VDSMS

1019

19A

156.950

156.950

Commercial. VDSMS

20

20

157.000

161.600

Port Operations (duplex)

1020

20A

157.000

157.000

Port Operations

1021

21A

157.050

157.050

U.S. Coast Guard only

1022

22A

157.100

157.100

Coast Guard Liaison and Maritime Safety Information Broadcasts. Broadcasts announced on channel 16.

1023

23A

157.150

157.150

U.S. Coast Guard only

24

24

157.200

161.800

Public Correspondence (Marine Operator). VDSMS

25

25

157.250

161.850

Public Correspondence (Marine Operator). VDSMS

26

26

157.300

161.900

Public Correspondence (Marine Operator). VDSMS

27

27

157.350

161.950

Public Correspondence (Marine Operator). VDSMS

28

28

157.400

162.000

Public Correspondence (Marine Operator). VDSMS

1063

63A

156.175

156.175

Port Operations and Commercial, VTS. Available only in New Orleans / Lower Mississippi area.

1065

65A

156.275

156.275

Port Operations

1066

66A

156.325

156.325

Port Operations

67

67

156.375

156.375

Commercial. Used for Bridge-to-bridge communications in lower Mississippi River. Intership only.

68

68

156.425

156.425

Non-Commercial. VDSMS

69

69

156.475

156.475

Non-Commercial. VDSMS

70

70

156.525

156.525

Digital Selective Calling (voice communications not allowed)

71

71

156.575

156.575

Non-Commercial. VDSMS

72

72

156.625

156.625

Non-Commercial (Intership only). VDSMS

73

73

156.675

156.675

Port Operations

74

74

156.725

156.725

Port Operations

77

77

156.875

156.875

Port Operations (Intership only)

1078

78A

156.925

156.925

Non-Commercial. VDSMS

1079

79A

156.975

156.975

Commercial. Non-Commercial in Great Lakes only. VDSMS

1080

80A

157.025

157.025

Commercial. Non-Commercial in Great Lakes only. VDSMS

1081

81A

157.075

157.075

U.S. Government only – Environmental protection operations.

1082

82A

157.125

157.125

U.S. Government only

1083

83A

157.175

157.175

U.S. Coast Guard only

84

84

157.225

161.825

Public Correspondence (Marine Operator). VDSMS

85

85

157.275

161.875

Public Correspondence (Marine Operator). VDSMS

86

86

157.325

161.925

Public Correspondence (Marine Operator). VDSMS

87

87

157.375

157.375

Public Correspondence (Marine Operator). VDSMS

88

88

157.425

157.425

Commercial, Intership only. VDSMS

AIS 1

AIS 1

161.975

161.975

Automatic Identification System (AIS)

AIS 2

AIS 2

162.025

162.025

Automatic Identification System (AIS)

*Channel 16 is the primary channel used for distress alerts.

*Channel 13 is the channel used to contact ship(s) during a critical collision danger. 

*Channel 22A is reserved for communication between US coast guards and private vessels. However contact must first be established on channel 16. 

Final Thoughts:

Now that you know a little more about VHF marine radios, their features and their use you can select the radio that will be best for you and your boating needs. Here you can find our list of best handheld VHF radios and best fixed mount radios.