SHIP-TO-SHORE H.F. COMMUNICATION
Schedule B
Watch is maintained as follows at Area Receiving
Stations for Calls from Ships--
Area Station.
Name.
Sydney
Ceylon
Bombay
Irirangi
Awarua
Vancouver
Singapore
Hong Kong
Call
Sign.
VIS*
VIS
VIS
VIS
GZP
GZP
GZP4
GZP5
VTF3
VTF4
VTF5
ZLO2
ZLO5
ZLB3
ZLB4
CKN
CKN2
CKN3
CKN4
CKN5
CKN6
GYL3
GYL4
GZO3
GZO4
Answering
Frequency
(kc/s).
6,463.5
8,662
12,952.5
17,160.5
4,283
8,566
12,849
16,875
8,566
12,849
16,835
6,393.5
16,835
8,554
12,831
4,740
6,393.5
8,290
12,831
16,845
22,533
8,554
12,831
8,554
12,831
Hours of
Watch-keeping.
G.M.T.
0900-1300
Continuous
Continuous
0000-1300,
2200-2400
0000-0200,
1600-2400
Continuous
Continuous
Continuous
0200-1600
Continuous
Continuous
Continuous
0000-0600,
1800-2400
Continuous
Continuous
0400-1000
Continuous
0000-0400,
1600-2400
On request
Continuous
Continuous
Continuous
Continuous
Frequency
Band (kc/s).
6,265.5-6,280.5
8,254-8,374
12,531-12,561
16,708-16,748
4,177-4,187
8,354-8,374
12,531-12,561
16,708-16,748
8,354-8,374
12,531-12,561
16,708-16,748
6,265.5-6,280.5
16,708-16,748
8,354-8,374
12,531-12,561
4,177-4,187
6,265.5-6,280.5
8,354-8,374
12,531-12,561
16,708-16,748
22,220-22,270
8,354-8,374
12,531-12,561
8,354-8,374
12,531-12,561

• April to September.
  † At other times by arrangement.
  SUPPLEMENTARY RECEIVING STATIONS
  The following stations are linked to the GBMS Organization.
  They should not normally be called direct nor have
  messages addressed to them, but they may offer to accept
  ship-shore H.F. traffic in order to expedite clearance.
  Station.
  Name.
  Coonawarra
  Vizagapatam
  Call
  sign.
  VHM3
  VHM4
  VHM5
  VTO3
  VTO4
  Answering
  Frequency
  (kc/s).
  8,554
  12,831
  16,835
  8,566
  12,849
  Hours of
  Watch-keeping.
  G.M.T.
  1000-2000
  Continuous
  2200-1000
  Continuous
  Continuous
  Frequency
  Band (kc/s).
  8,354-8,374
  12,531-12,561
  16,708-16,748
  8,354-8,374
  12,531-12,561
  Authority.-Admiralty. (H. 6048/53.)
  Wellington, N.Z., 15 December 1953.
  W. C. SMITH, Secretary for Marine.
  (M. 10/145)
  Notice to Mariners No. 3 of 1954
  (This notice repeats parts of Admiralty Notice to Mariners
  No. 3B of 1954)
  3B. OFFICIAL RADIO MESSAGES TO MERCHANT
  SHIPS-THE MERCAT SYSTEM
  Former Notice 3B/53 cancelled.
  NOTE.-The substance of this Notice will not be
  reproduced in Admiralty Lists of Radio Signals or in Notices
  to Ship Wireless Stations.
  Amendments will be published weekly in Section VI of
  Weekly Complete Editions, Admiralty Notices to Mariners
  (Corrections to Admiralty Lists of Radio Signals and Notices
  to Mariners 3, 3A, and 3B).
  IT IS IMPORTANT THAT MASTERS ENSURE
  THAT THIS NOTICE IS AVAILABLE TO AND
  UNDERSTOOD BY THEIR RADIO OFFICERS. AN
  EXTRA COPY IS SUPPLIED FOR THE USE OF RADIO
  OFFICERS.
  GENERAL

1. This Notice describes an alternative organization to that
   described in N.Z. Notice to Mariners 2 whereby official
   messages can be passed to Merchant ships.
2. This organization is known as the MERCAT System
   and will not be brought into force until so ordered by the
   Admiralty. It is an expansion of the GBMS organization
   which it would supersede, and provides for fuller world-wide
   coverage.
3. Each Area is covered by one High-powered shore
   Radio Station which broadcasts on low and/or high frequencies
   simultaneously on fixed schedules. Medium-power short range
   coastal radio stations also broadcast MERCAT messages to
   ships estimated to be within range. The initial call on
   500 kc/s will be followed by the operating signal directing a
   shift to the working frequency. After a brief interval the
   message will be broadcast. Messages will be broadcast
   immediately on receipt and will be repeated at the next
   single-operator period.
   Details of special routines for United Kingdom 500 kc/s
   Coastal Stations will be found under Area IV.
4. Details of the numbered MERCAT areas and
   particulars of the participating areas and coastal stations are
   shown later in this Order. Fuller details of the radio
   organization will be contained in a publication which will be
   issued to Merchant Ships when necessary.
   LETTERED MESSAGES
5. General Messages issued by the Admiralty intended
   for Merchant Ships in all areas world-wide are identified by
   the word MERCAT followed by double letters in alphabetical
   sequence, e.g.
   AA - AZ
   BA - BZ
   contained in the text.
   In addition to these world-wide General Messages there
   are two other series of general messages. One is applicable
   to Merchant Ships in the Atlantic Ocean area only, and the
   other to Merchant Ships in the Pacific area only. These are
   known as the MERCATLANT and MERCATPAC Series
   respectively. These series are identified in the same manner
   as the world-wide series except that the letters will be
   prefixed by "MERCATLANT" and "MERCATPAC"
   as appropriate. Those messages which are not of an emergency
   or urgent nature will be disseminated to Naval Authorities
   who will deliver them to Masters upon arrival in port. Such
   general messages will contain the same identifying features
   as if they had been broadcast. When a MERCAT lettered
   message has been sent to the Naval Authorities for delivery
   the next MERCAT general message broadcast to ships at sea
   will contain information to this effect and indicate the
   identifying letters of such message. Merchant ships will
   thus be able to determine whether they have received all
   messages in each series.
   CALL SIGNS
6. Collective call signs to which general messages
   concerning British ships will be addressed, are as follows:
   NUKO All ships guarding MERCAT.
   NRMS All Allied Merchant Ships.
   NRMS 1 to 13 All Allied Merchant Ships in Area
   indicated.
   GBMS All British Merchant Ships.
   GBMS 1 to 13 All British Merchant Ships in Area
   indicated.
   Areas are those shown in the diagram attached; e.g.
   NRMS 3 All Allied Merchant Ships in Mercat
   Area III.