Maritime Safety Information (MSI) 

Maritime Safety Information which includes both weather information and navigational warnings is broadcast on VHF by the Coastguard Maritime Rescue Co-ordination Centres (MRCC) every three hours. 

The content of these broadcast and the schedule to which they are issued is published in the MCA's MSI Leaflet. 

An announcement is made on CH 16 as an alert to the broadcast, detailing the channel that should be selected - as published on the final page of the MSI leaflet.

The content of the broadcast that follows will vary depending on the time of day it is being transmitted.

Coastguard MRCC                   Routine	B	C	A	C
Thames & Dover, Brixham & Falmouth,  Belfast, Stornoway & Shetland	0110 1310	0410 1610	0710 1910	1010 2210
Solent & Portland,  Liverpool, Aberdeen & Forth	0130 1330	0430 1630	0730 1930	1030 2230
Swansea, Milford Haven & Holyhead, Humber & Yarmouth	0150 1350	0450 1650	0750 1950	1050 2250
Clyde	0210 1410	0510 1710	0810 2010	1110 2310

A: Full MSI broadcast including a new inshore waters forecast and the outlook for the following 24hrs. This is preceded by gale warnings and an excerpt from the shipping forecast and is followed by WZ navigational warnings and where appropriate SUBFACTS, GUNFACTS and the three day fisherman’s forecast.

B: A new inshore waters forecasts is broadcast together with a new outlook for the following 24hrs and any gale warnings.

C: A repetition of the most recently issued inshore waters forecast and gale warnings, plus new strong wind warnings.

MSI is broadcast in local time such that the 'clock time' that the broadcasts will be received at will remain the same throughout the year.

MSI is also issued by the coastguard on the NAVTEX frequencies. Information that the UK is required by international convention to transmit is issued on 518kHz backed up by further useful information on 490kHz such as actual weather conditions as recorded by selected weather stations around the UK coast.  Details can be foudn in the MCA MSI leaflet.

Navgational warnings (WZ) for NAVAREA1 and the UK Coast can can also be obtained from the UKHO web-site. Many of these warnings are of a temporary nature, but others may remain in force for several weeks and may be superseded by Notices to Mariners.

Rigmoves and pipe laying operations have been deemed to be sufficiently visible by sight, by radar and through local navigation warnings, therefore these will not be included with the VHF MSI broadcasts (NAVTEX remains unchanged).