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VHF Marine Monitoring

Last updated on 06-15-13.

Here you will be introduced to VHF marine monitoring, which is a must if you live near a navigable waterway such as an ocean, the Mississippi River system, or our own Great Lakes.  I have always had an interest in marine monitoring due to our close proximity to Lake Erie, and it can provide you with many different types of scanning excitement.  There are no specific marine frequencies for any given location in this area; the nationally allocated VHF band plan is utilized and can be monitored just about anywhere.


In the United States, there is a block of frequencies set aside between 156 and 158 MHZ for marine communications, as well as a band that is partially shared with other services in the 161 to 162 MHZ area.

One heavy user of the marine bands is the United States Coast Guard (USCG).  As quiet as you might think these frequencies would be, there is really quite a bit of traffic to listen to.  In our area, the USCG operates regularly on the air, with rescues, marine assistance, vessel traffic control, etc.  Channels such as 16, 21, 22, and 23 are frequently used in our area by the USCG.

Also used by these frequencies is the Canadian Coast Guard.  The Canadian agency uses the international marine channel plan, which uses many of the same frequencies as the US plan but with some differences.  Channels 11, 12, 16, 65, and 85 are heavily used.  While I will note frequencies that will be interesting to listen to for the Canadian Coast Guard, this section is geared toward US monitoring, and my knowledge of Canadian usage is by no means complete.

Commercial traffic is common on the marine band.  That includes vessels with cargoes to be sold for a profit, as well as other operations that are related to maritime interests and are used for a profit.

One of the busiest sections of the band is used by noncommercial operators.  This includes small marinas, and, more so, recreational boater traffic.  That includes leisure vessels and fishing vessels.


The USCG is broken up into a system of “Sectors” and “Stations.” The “sectors” are large USCG operating centers that cover large geographic areas.  Our local sector, “Sector Buffalo,” covers Lake Ontario and the eastern half of Lake Erie.

Within the jurisdiction of the sectors are “Stations.” Stations generally have smaller areas of control and deal with more of the nitty-gritty marine work.  If a rescue operation must occur in our local area, our station, “Station Erie,” will be the governing body.

Coast Guard sectors and stations often have “operating channels.” If anything will happen, besides an emergency on Channel 16 (see below), operations will occur on this channel.  Locally the channel is 21A; it can vary.


EMERGENCY, Calling: These frequencies are used when one vessel/station wants to call another.

Channel 16 is one of the most important frequencies in monitoring Marine Communications.  This is the international distress and calling frequency used worldwide in maritime interests.  If a vessel is in distress, they will make contact with the Coast Guard on this channel.  Someone requesting a radio check or who needs to speak to the Coast Guard will call here before moving to another channel.  Also, vessels wishing to speak to another ship can call here before moving to one of the noncommercial channels.

Marine channel 13 is used like a secondary backup to channel 16 mainly in inland navigable waterways.  Locations and intentions of commercial vessels must be periodically announced here.

Finally, Channel 9 is used as an alternative calling frequency, mainly for recreational boaters.  It was assigned with this purpose with the intention of removing pleasure boater calling off of Channel 16.

PORT OPERATIONS: Port Operations frequencies are used mainly at large ports for the direction of vessels in the port.  Docking and undocking operations can be heard here, as can tugboats coordinating with other vessels; also, “Harbor Controls” direct ships through the port.  I personally have none of these in use in my area so do not know much about them.

COMMERCIAL: Commercial channels are used by anyone who intends to be making money by using the water.  Fisheries, launching services, and tugboat operations can be heard here, as can anything that brings in a profit.

NONCOMMERCIAL: These channels are some of the busiest in my area.  These are more leisure activities.  That includes marinas, and, more so, pleasure boat traffic between fishermen and recreational boaters.

PUBLIC CORRESPONDENCE: Public correspondence blocks were cut out of the marine band to act as a marine telephone.  Someone on a ship can “place a call” to a shore station, and it will be patched through.  The ship will transmit on one frequency, and the shore station will transmit on another, making these duplexes.  These are very slow to nonexistent now that cell phones are in use; I monitor them only because they are major operating channels for the Canadian Coast Guard.

COAST GUARD OPERATIONS: These are listed as “CG Ops” in the list.  Besides having a constant monitor on channel 16, any given Coast Guard office will also have a working channel, for traffic with Coast Guard vessels and for rescue coordination efforts.  Some CG offices may also monitor a port operations channel if necessary.

VESSEL Traffic SERVICES: VTS frequencies are used by CG offices at very busy ports.  The CG office will keep an eye on vessels via radar and will update them on their location, proximity to other vessels, nearby hazards, etc.  These channels are not in use in my area.


Frequencies are all in simplex.  That means that you may only hear one side of the conversation, depending on your proximity to a station.  If a frequency is part of a duplex, the other half of the duplex will follow, with ship transmit channel first and ship receive channel second.  Refer to the “Notes” list below the frequencies for reference points to numbers in parentheses after a frequency.

Frequency (MHZ): channel number: usage

156.05: 01A: port ops/commercial, VTS New Orleans/Lower MS.  River area

156.25: 05A: port ops/VTS, Houston, New Orleans and Seattle areas

156.30: 06: intership safety

156.35: 07A: commercial

156.40: 08: commercial, intership.  Used by Lakeshore Towing in the Erie area.

156.45: 09: boater calling freq (1)

156.50: 10: commercial

156.55: 11: commercial, VTS in some areas (2)

156.60: 12: port ops, VTS in some areas (3)

156.65: 13: intership navigation safety (4)

156.70: 14: port ops, VTS in some areas

156.75: 15: environmental (ship receive only)

156.80: 16: international distress and calling freq, emergency (5)

156.85: 17: “state control” (maritime law enforcement)

156.90: 18A: commercial

156.95: 19A: commercial

157.0: 20: port ops (duplex with 20A)

161.60: 20A: port ops (duplex with 20)

157.05: 21A: CG ops (6)

157.10: 22A: CG maritime safety/rescues (7)

157.15: 23A: CG ops (6)

157.20: 24: public correspondence (duplex) (8)

161.80: 24: public correspondence (duplex) (8)

157.25: 25: public correspondence (duplex) (8)

161.85: 25: public correspondence (duplex) (8)

157.30: 26: public correspondence (duplex) (8)

161.90: 26: public correspondence (duplex) (8)

157.35: 27: public correspondence (duplex) (8)

161.95: 27: public correspondence (duplex) (8)

157.40: 28: public correspondence (duplex) (8)

162.00: 28: public correspondence (duplex) (8)

156.175: 63A: port ops, commercial, and VTS in the New Orleans/Lower MS.  River area

156.275: 65A: port ops (9)

156.375: 66A: port ops

156.375: 67: commercial, bridge to bridge (intership)

156.425: 68: noncommercial

156.475: 69: noncommercial

156.575: 71: noncommercial

156.625: 72: noncommercial, intership only

156.675: 73: port ops

156.675: 74: port ops

156.875: 77: port ops, intership only

156.925: 78A: noncommercial

156.975: 79A: commercial.  Noncommercial allowed in Great Lakes

157.025: 80A: Commercial.  Noncommercial allowed in Great Lakes.

157.075: 81A: CG environmental protection ops

157.125: 82A: CG ops

157.175: 83A: CG ops

157.225: 84: public correspondence (duplex) (8)

161.825: 84: public correspondence (duplex) (8)

157.275: 85: public correspondence (duplex) (8)

161.875: 85: public correspondence (duplex) (8)

157.325: 86: public correspondence (duplex) (8)

161.925: 86: public correspondence (duplex) (8)

157.425: 88A: commercial, intership only

Notes Reference

1: Channel 09 is used as a calling frequency for vessels with either commercial or noncommercial intentions.  Once contact has been established, the parties will usually move to another channel.

2: Channel 11 appears to be used as a canal control channel or VTS sort of thing, at least in my area, for Canadian traffic.  Welland Control is controlled here.

3: Channel 12 is used by the Canadian Coast Guard as a vessel traffic control channel.

4: Channel 13 is a “second 16” for safety purposes, as compared to 09 as a “second 16” for calling purposes.  All larger vessels in mainly inland waterways need to announce their location and intentions periodically here.

5: Channel 16 is a “necessity” in marine monitoring.  Ships must carry a radio listening on Channel 16, and emergency calls, boater assistance requests, and urgent messages will be found here.

6: Channels 21A and 23A are CG operating channels.  21A is the primary operating channel for the USCG in my area.  Coast Guard vessels will communicate on these channels with their station, and with each other, as well as coordinating rescue operations.  Another must-have.  These frequencies may be used as the “working channel” for a CG station.

7: Channel 22A is a universal, nationwide CG/VESSEL communication channel.  CG will announce safety information here, such as assistance requests or weather bulletins, and rescue communications may occur here.

8: Channels 24 through 28 and 84 through 86 are all known as “Public Correspondence” channels, or “Marine Telephone,” where persons onboard a vessel can place a call to a shore station.  These channels are rarely used or even obsolete now that cell phones are popular.  These are also major operating channels for the Canadian Coast Guard.

9: Major operating channel for the Canadian Coast Guard.

Notice: I personally monitor all these frequencies in my scanners for US and Canadian marine traffic on the Great Lakes.  You may not want to monitor all these frequencies in your area; if you are not located near the coast, the Great Lakes, or the Mississippi River, these channels will be dead and there is no reason to monitor them (unless you’re interested in hearing persons who have recently begun carrying marine radios on land and using them illegally)!


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