This brief overview will describe how HMCS HAIDA would have communicated in fleet exercises. Figure 1 illustrates a very basic organizational chart of a naval fleet. The fleet could be comprised of ships of one country or they could be multi-national in scope. Ships of various navies participated in exercises that tested their abilities to work as co-ordinated and unified force. Here are some of the different fleets that were assembled for exercises during the 1950's and 1960's:

NATIONAL - The fleet of ships from one country only.
CANUS - Ships of Canada and the United States.
CANUK - Vessels of Canada and the United Kingdom.
NATO - A force of ships from member countries of N.A.T.O.
ALLIED - NATO vessels plus those of Australia or France.


1) Each level has a numeric designation.
2) Numbers in parenthesis denote number of ships.
3) The whole fleet must have a communications plan.

Commander Robert Willson (Ret'd) of Toronto Ontario, provides a detailed description of a NATO Communications Plan.

"During fleet exercises, there are numerous disciplines which must be mastered, however, one of the more important items is radio communications. Generally speaking, the American fleet has been equipped with the latest advances in naval electronics technology and other countries would tend to lag behind the United States to some degree. In order to ensure that participating ships have sufficient radio resources, NATO developed a standard to ensure that each participating ship in any exercise had a minimum of seven (7) radio circuits (sometimes referred to as channels) within designated frequency bands.

In order to communicate with each other, RCN ships used a Communications Plan which defined radio circuits and relevant frequencies to use. The plan generally stayed in use for many years before being modified. If necessary, a much more complex plan could be drawn up for a large NATO fleet exercise. The plan represented in Table 1 is very basic in scope, however, it serves as a good example. Different Communications Plans were sometimes used by various Task Groups within the Task Force and frequencies within a plan were often shifted to overcome mutual interference or jamming by the opposition. VHF and UHF circuits were non-encrypted voice (AM) or in limited cases, MCW (modulated CW).

As an example, the Commander of Task Force 302 orders TG 302.1 to set watch on 04B. In turn, the ships in TG302.1 look at line 04 in COMPLAN B and tune to the indicated frequency on the PRITAC circuit. Usually, the arrangement would be for the Task Force Commander to order a shift to COMPLAN B. All ships in the TG then switch to the frequency listed in column B for all of the circuits which are listed. Some of the other Watch orders gave consideration for guarding distress frequencies. The primary method of communications between ships was voice. Officers on the bridge would use the PRITAC (UHF) radio circuit to control and co-ordinate movements".

TASK GROUP COMMON 277.3 277.5 277.7 277.9
MILITARY DISTRESS 243.0 243.0 243.0 243.0
INT'L DISTRESS 0.500 0.500 0.500 0.500
PRITAC 278.2 283.1 325.7 343.3
SECTAC 2.210 2.210 2.210 2.210
CI (P) 325.2 292.2 292.5 292.8
CI (S) 4.250 4.350 4.450 4.650
EW (P) 340.5 340.7 340.8 340.0
EW (S) 2.350 2.450 2.650 2.800
ASP1 (P) 350.3 352.4 357.2 359.8
ASP2 (S) 360.1 361.3 363.4 364.7
SAU1 (P) 365.2 365.4 366.3 367.1
SAU2 (S) 370.7 371.2 373.5 374.1
MARITIME DISTRESS 2.182 2.182 2.182 2.182
HS1 (P) 365.7 376.5 377.1 378.9
HS2 (P) 380.0 381.1 383.6 384.2
VHF DISTRESS 121.5 121.5 121.5 121.5
ADMIN (See note 1) 3.275 3.275 3.275 3.275
L/L 391.2 391.4 391.5 391.7


Except for distress, the above frequencies were not the actual ones used and are only shown here for illustrative purposes.

Note 1: In the 1960's time frame, this circuit was known as TGC (Task Group Common) and functioned as an intership administrative CW circuit.


  • Line means the line number in the Communications Plan.
  • Circuit is the operational definition of a radio channel.
  • Column A,B,C,D etc defines a frequency in a specific COMPLAN for a task group or task force.


    Used for passing administrative or long tactical messages.


    Primary Tactical and Secondary Tactical - These circuits were used by the  bridge. They were reserved for short messages dealing with movements of ships and had to be dealt with immediately upon receipt.  PRITAC was reserved exclusively for manoeuvring, alarm reporting and urgent operational messages. All messages heard on PRITAC were recorded in the Tactical Log.

    CI (P or S)

    Combat Information Primary or Secondary. Used between OPS Rooms primarily by officers, radar plot or weaponmen..

    EW (P or S)

    Electronic Warfare Primary or Secondary. Used between Electronic warfare rooms.

    ASP1(P) or 2(P)

    Anti-Submarine Patrol, Force 1 or 2 Primary. Assigned for fixed wing aircraft.

    SAU1(P) or 2(P)

    Search And Attack Unit, Force 1 or 2 Primary. Comprised of ships, aircraft and helicopters.

    HS1(P) or 2(P)

    Helicopter to Ship, Force 1 or 2 Primary.


    Naval Administrative Radio Net. It was used for messages dealing with logistics, personnel, conduct of exercises etc.
    Administrative traffic was usually more cumbersome than tactical traffic.


    Land/Launch. This circuit was used by shipboard aircraft to communicate with their 'controller' during launching or landing on. They would then shift to the ASP or SAU frequencies once they were 'on task'.

    Screen Common - This is a tactical circuit used for communications within the screen of a large formation. The Screen Commander uses this circuit in a manner similar to that of the PRITAC circuit. Ships of the screen may be ordered to close down PRITAC when Screen Common is being used.  This was generally done to reduce the men required on each watch.

    Watch Definitions:

    L - Listen (receive only)
    G - Guard (receive watch - transmitter tuned and ready for use)
    C - Copy - receive and transmit as required. Maintain a continuous log.
    1 - For private ship or when there is only one ship in the group.

    An example of using the Communications Plan:

    To illustrate the use of the "plan", let's use the following example. Suppose Task Force A discovers a submarine at co-ordinate X and needs additional air support from Task Force B. Task Force A is using circuit SAU1(P) and Task Force B is using SAU2(P). Once the 'B' aircraft are in a position to join forces, then they must switch to the SAU1 circuit. When 'B' aircraft are no longer needed, they will return to Task Force B and switch back to the SAU2(P) circuit.

    Ernest Cable, historian for the Shearwater Aviation Museum, adds this. " The surface navy had very real problems converting to UHF! In the 1960's the surface navy required a separate UHF radio for each circuit and trying to get them to change frequency during coordinated air-sea exercises was like pulling hens' teeth. The frequency change route from the ship's operations room to the radio room was convoluted because it hadn't changed since the times of Nelson. The aircraft talked to the air controller in the Ops Room, who had to get permission from the Ops Officer, who had to get permission from the Captain, which was relayed back down to the Ops Officer who passed the order to the Communications Officer, who had devise a new communication plan then pass the order to the Leading Seaman in the radio room to change frequency on one of the UHF radios. In those analogue days, the radio room was one of the busiest places in the ship, so it took the poor L/S 10-15 minutes to change the frequency. Then the changed frequency message came back up the chain of command and the air controller finally attempted to call the aircraft on the new frequency. By this time the reason for changing frequency had long past.  The aircraft was still monitoring the old frequency and the air controller was frustrated because the aircraft wasn't responding on the new frequency. The problem was solved by having aircraft UHF radios installed at the air controllers console where the air frequencies could be changed with the twist of a rotary dial and the ship's communication plan wasn't totally messed up."

    Credits and References:

    1) Signalman Trade Group One Manual BRCN 3038(63). Published by RCN, 1960; revised 1963.
    2) Cdr Bob Willson . RCN Ret'd.
    3) Ernest Cable <erncar(at)>


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    July 10/09