Onboard communications
The notes referring to the VHF 'Table of Transmitting frequencies
, in ALRS show that two of the 'intership' channels - Ch15 and Ch17- 'may also be also be used for on-board communications' - meaning
between the bridge and handheld VHF radios on deck. When used for
onboard communications, power output should always be limited to
one watt (some equipment automatically selects 1 W when you switch to
Ch 15/17). The Callsigns to be used are 'Ship Name Control' for the bridge,
and 'Ship Name Alfa' 'Ship Name Bravo' ... etc., for the handheld
sets - e.g.,
Ch 17 ' Wizard Control this is Wizard Delta -Over'
(Handheld calling the bridge)
You will see from the VHF 'Table of Transmitting Frequencies
that channels 01-28 and 60-88 only, are listed. These channels are the
main 'international' list. Channels 29-59 are available for allocation as
'private' channels - for 'private business' use in shore stations (e.g., oil
depots) - but also to some ships as additional 'onboard' channels. If
your vessel has a special requirement for additional onboard channels,
the radio licensing authority for your ship'S country of registration is
responsible for allocating those additional channel(s).UHF Radio - Onboard Communications
Onboard communications may also be carried out on non-GMDSS
equipment, like UHF radio equipment, fitted specifically for this
purpose. The same type of callsigns should be used on UHF
channels as is shown above for Marine VHF, when used between the
bridge UHF radio and the handheld UHF radio equipment on-deck.
You need to follow the manufacturer's instructions concerning battery-
charging and general care and maintenance of the UHF equipment.Public Correspondence (PC) Services
Public Correspondence (PC) services are 'pay' services, for:
Telephonelfax.
Telex.
e-mail/ data calls and messages.
Calls/messages may be made using GMDSS equipment including:
Marine VHF Radio; Marine SSB Radio; and/or Inmarsat systems - or, in
some cases, by Cellular radio and non-G MDSS Mobile Satellite Services.46 THE NAUTICAL INSTITUTE