Guidance

Advice Note 1033 - Maritime Safety Information (MSI) Leaflet

Updated 4 April 2025

Introduction

Maritime Safety Information (MSI) is a collective term used to describe navigational and meteorological warnings, meteorological forecasts and other urgent safety related messages that ships require to safely navigate.
The MSI Service is a co-ordinated network of broadcasts designed to harmoniously disseminate MSI to all seafarers navigating within particular sea areas. The service supports one of 9 key functional requirements of the Global Maritime Distress and Safety System (GMDSS); “every ship, while at sea, shall be capable of receiving MSI.” 

The principal objective of this service is to provide simple, sustainable, and robust methods of delivery and present information in a consistent fashion that is ubiquitous and easy to assimilate by all seafarers. Currently, there are two approved methods of promulgating MSI:

• by the international Navigational Telex (NAVTEX) Service (518kHz) and
• by Enhanced Group Call (EGC), via a Recognised Mobile Satellite Service (RMSS).

The Safety of Life at Sea Convention (SOLAS) 1974, as amended, mandates the provision of this Service, and the receipt of MSI by SOLAS or nationally compliant vessels. However, MSI is considered of vital concern to all vessels and every effort should made by all seafarers to receive it. Therefore, in addition to the approved broadcast methods above, the UK also broadcast MSI by VHF and MF radiotelephony (RT) to make the information available to those that are not ‘Mandated’ to receive it.

1. UK MSI Service

1.1 The Maritime Coastguard Agency (MCA) is responsible for the provision of the UK’s MSI Service. The MCA ensures that the service fulfils the requirements of both national and international regulations and policies and maintains oversight of the following components:

• The UK Navigational Warning Service, provided by the United Kingdom Hydrographic Office (UKHO).

• The UK Marine Weather Service, provided by the Met Office.

• The UK’s NAVTEX Service, provided by the MCA.

• International EGC Services, provided by RMSS - currently Inmarsat’s SafetyNet Services and Iridium’s SafetyCast Service.

• Radiotelephony (RT) Broadcast services, provided by the MCA.

Figure 1 - High-level Structure of the UK MSI Service.

2. Navigational Warning Service

2.1 The UKHO acts as the National Co-ordinator and NAVAREA I Co-ordinator for the UK. They are responsible for assessing, selecting, and issuing Coastal Navigation Warnings (known in the UK as WZ’s) and NAVAREA I Warnings.

2.2 The principal methods for broadcasting these warnings are by the International NAVTEX Service and by the International EGC Service. WZ warnings and selected NAVAREA I warnings are also broadcast to 1 or more of the 19 Coastal Warning Areas (see Figure 4) by VHF and MF through appropriate coast radio stations; on receipt and at twelve hourly intervals until cancelled.

2.3 WZs use the UK Shipping Forecast Service areas as a naming convention to describe the general area of a warning’s location (see Figure 2).

2.4 Rig movements (RIGMOVES) are also issued by the UKHO on receipt of a notification by the Rig (WZ RIGMOVE). These movements are prolific and because of their temporary nature, they are typically not included in any broadcast (unless the final position is in an area that is particularly hazardous, such as Traffic Separation Scheme (TSS) or busy sea lane). Each week a cumulative list of positions for all known Mobile ‘Rigs’ within NAVAREA I is published and broadcast via the EGC Service as a NAVAREA I warning.

2.5 All “in force” WZ and NAVAREA I warnings are also available on the UKHO website at: https://msi.admiralty.co.uk/RadioNavigationalWarnings.

2.6 Any information pertaining to the safety of navigation should be shared with the UKHO’s Radio Navigation Warning (RNW) team as soon as possible (available 24 hours a day), either directly or via nearest UK Coastguard Maritime Rescue Co-ordination Centre (MRCC). For more information, see the MCA’s Navigational Warning Service leaflet (https://www.gov.uk/government/publications/navigational-warnings-reporting-and-broadcasting-hazards-at-sea/navigational-warnings ).

3. UK Marine Weather Service

3.1 The Met Office act as the METAREA I and National issuing and preparation service for the UK. The primary products provided by the Met Office as part of the UK’s Marine Weather Service are:

• Inshore waters forecasts

• Strong Wind Warnings (Beaufort Force 6, 22 knots or above)

• Shipping Forecast (for 31 Shipping Forecast Areas around and approaching the UK)

• Shipping Forecast 24 hours outlook.

• Extended 3-day outlook (post Shipping Forecast outlook).

• Gale Warnings (Beaufort Force 8, 34 knots or above)

• High Seas Forecast (for 13 ‘Deep Water’ areas of the North Atlantic within METAREA I)

• Storm Warnings (Beaufort Force 10, 48 knots or above)

3.2 Additional services provided by the Met Office include:

• Fishing Fleet Forecast. Issued between 1st of October and 31st March, comprising of 4 areas around the UK:

   - Northern North Sea, broadcast by Aberdeen MRCC

    - Southern North Sea, broadcast by Humber MRCC

    - Southwest Approaches, broadcast by Falmouth MRCC

    - Northwest, broadcast by Shetland MRCC

3.3 Weather Actuals or Coastal Reports – Real time weather observations intended for validation.

4. BBC Radio Broadcasts

4.1 The BBC broadcast some of the Marine Weather Information provided by the Met Office as follows:

WEEKDAYS (Monday to Friday)
00:48 (Local time)	Gale Warnings, Shipping Forecast, weather reports from coastal stations and the Inshore Waters Forecast.
05:34 (local time)	Gale Warnings, Shipping Forecast, weather reports from coastal stations and the Inshore Waters Forecast.
Weekends (Saturday and Sunday)
00:48 (local time)	Gale Warnings, Shipping Forecast, weather reports from coastal stations and the Inshore Waters Forecast.
05:34 (local time)	Gale Warnings, Shipping Forecast, weather reports from coastal stations and the Inshore Waters Forecast.
17:54 (local time)	Gale Warnings and Shipping Forecast.

Table 1 - BBC RADIO 4 FM SCHEDULE

Note: Whilst a dedicated Long Wave (LW) broadcast by the BBC of the Shipping Forecast ceased on 31 March 2024, the broadcast of Marine Weather Information via the BBC is available at the above schedule on FM BBC Radio 4 or via BBC Sounds. LW broadcasts may continue at the discretion of the BBC and its partners at the above schedule. A full suite of Marine Weather Information is also available on the BBC Weather Coast and Sea website: https://www.bbc.co.uk/weather/coast-and-sea.

Figure 2 - Shipping Forecast Areas and Coastal Warning General Areas

Figure 2 Shipping Forecast Areas and Coastal Warning General Areas (Green). © Crown Copyright 2024. All rights reserved. Reproduced from Admiralty List of Radio Signals (ALRS), UK Hydrographic Office. NOT TO BE USED FOR NAVIGATION.

5. UK Navtex Service

5.1 The principal method for the dissemination of UK MSI is through the International NAVTEX Service. The MCA is responsible for delivering this service and UK coverage is provided out to 300 miles from the following stations (see Figure 3 - NAVTEX Service Areas):

• Cullercoats station [G]
• Niton station [E]

• Portpatrick station [O]

  5.2 In addition to these stations, WZ warnings are also broadcast by the Belgium Administration via Oostende NAVTEX Station [V], primarily to cover the Thames Estuary and approaches.

  5.3 Select Inshore Waters Forecasts and Shipping Forecasts are also broadcast by the Irish Coastguard, via Malin Head ([Q] and [A]) and Valentia ([W]) NAVTEX Stations (see Table 2 and Table 3).

  5.4 NAVTEX Stations are each allocated a special B1 character that identifies the aerial (for example [Q] – Malin Head International Service on 518 kHz). Stations will only provide information that falls within its declared service area and therefore it is important to select the appropriate B1 characters for the area in which a vessel is travelling towards as well as the area it is currently operating in.

  5.5 Any broadcast issues relating to NAVTEX should be addressed to the nearest MRCC or UK NAVTEX Co-ordinator on 0344 382 0043.

Figure 3 – NAVTEX Coverage. © Crown Copyright 2024. All rights reserved. Reproduced from Admiralty List of Radio Signals (ALRS), UK Hydrographic Office. NOT TO BE USED FOR NAVIGATION.

6. International Navtex Schedule

6.1       UK MSI is transmitted by NAVTEX on the International Frequency 518 kHz, in English, at the following times (UTC):

.	Cullercoats [G]	NITON [E]	PORTPATRICK [O]	OOSTENDE [T][V]	VALENTIA [W] (For sea areas Irish Sea, Sole, Fastnet and Shannon)	MALIN HEAD [Q] (For sea areas Shannon, Rockall, Malin, Bailey and Hebrides)
Gale warnings [B]	On receipt and at 0100, 0500, 0900, 1300, 1700, 2100.	On receipt and at 0040, 0440, 0840, 1240, 1640, 2040.	On receipt and at 0220, 0620, 1020, 1420, 1820, 2220.	On receipt and at 0310, 0710, 1110, 1510, 1910, 2310. *	On receipt and at 0340, 0740, 1140, 1540, 1940, 2340.	On receipt and at 0240, 0640, 1040, 1440, 1840, 2240.
Shipping Forecast 24- and 48-hour outlook [E]	0900 and 2100.	0840 and 2040.	0620 and 1820.	0710 and 1910. *	0740 and 1940.	0640 and 1840.
High Seas forecast [E]	-	-	-	-	1140 and 2340	1040 and 2240
Extended Outlook (3-5 Days) [E]	0100	0040	0220	-	-	-
WZ Coastal Navigation Warnings [A]	On receipt (where applicable) and at 0100, 0500, 0900, 1300, 1700, 2100.	On receipt (where applicable) and at 0040, 0440, 0840, 1240, 1640, 2040.	On receipt (where applicable) and at 0220, 0620, 1020, 1420, 1820, 2220.	On receipt (where applicable) and at 0330, 0730, 1130, 1530, 1930, 2330.	-	-
NAVAREA I Navigation Warnings [A]	On receipt (where applicable) and at 0500 and 1700.	On receipt (where applicable) and at 0440 and 1640.	On receipt (where applicable) and at 0220 and 1420.	-	-	-
FOSNI Submarine and Gunnery Exercises [L]	-	-	On receipt (where applicable) and at 0620 and 1820	-	-	-
FOST Submarine and Gunnery Exercises [L]	-	On receipt (where applicable) and at 0440 and 1640	-	-	-	-

Table 2 - International NAVTEX Schedule

*Note: Weather information broadcast from Oostende is from Belgian sources not the Met Office.

7.  National Navtex Service Schedule

7.1 Inshore Waters Forecasts, Strong Wind Warnings and Weather Actuals (coastal observations) are transmitted by NAVTEX on the National Frequency 490 kHz, in English, at the following times (UTC):

	CULLERCOATS [U]Areas 1 to 5 and 18	NITON [I] Areas 5 to 9 and 19	PORTPATRICK [C] Areas 9 to17	MALIN HEAD [A] Areas 13 to 17
Inshore Waters Forecast [E]	0720, 1120, 1920 and 2320	0120, 0520 1320 and 1720	0020, 0820 1220 and 2020	0000, 0400, 0800, 1200, 1600 and 2000
Strong Wind Warnings [B]	On receipt, once only.	On receipt, once only.	On receipt, once only.	-
Weather actual reports – Coastal Observations [V]	On receipt, once only.	On receipt, once only.	On receipt, once only.	-

Table 3 - National NAVTEX Schedule (See Figure 3 for Inshore Waters Forecast Areas)

8.  Radiotelephony Broadcast Services

8.1 The NAVTEX Services are complemented by both VHF and MF RT broadcasts. The MCA provides VHF coverage out to approximately 30 nautical miles  and MF coverage out to approximately 150 miles using its network of remote aerial sites around the UK coast.

8.2 MSI will be broadcast by the MCA on either VHF channels 62, 63 or 64, as part of the following routines and schedule. To reduce interference and ensure simultaneous broadcasts of MSI, VHF Channel 10 may also be used.  An initial announcement will be made on VHF Channel 16, directing seafarers to a working channel.

8.3 In addition to the routine broadcast, Gale, Storm and Navigation Warnings will be broadcast when received (where appropriate) and should be announced by a Digital Selective Calling (DSC) alert prior to transmission.

8.4 New Inshore Waters Forecasts are issued daily, every six hours from 0500 UTC and are broadcast every three hours, either as a repeat or new forecast. Shipping Forecasts for UK sea areas are broadcast twice daily. Gale Warnings for UK sea areas are broadcast as soon as possible after they are received and are valid for 24-hours unless cancelled. Any Gale Warning still in force after the 24-hour period will be renewed.

8.5 A Strong Wind Warning will be issued if the wind speed in an Inshore Waters Forecast area is predicted to be Force 6 or more and was not identified in the previous Inshore Waters Forecast. Strong Wind Warnings are valid only until the next new Inshore Waters Forecast. These warnings will be broadcast on receipt and may be included in the repetition broadcast. The legend ‘SWW’ will be included in the Inshore Waters Forecast to indicate that a Strong Wind Warning is in effect for the time covered by the forecast.

8.6 MF RT Broadcasts are scheduled broadcasts only (see Section 9). Information will be transmitted on the following frequencies, with an initial announcement on 2182 kHz:

CONTROLLING MRCC	MF RADIO SITE	FREQUENCY	SCHEDULE
Belfast	Tiree	1883 kHz	08:10 and 20:10
Shetland	Collafirth	1770 kHz	07:10 and 19:10
Stornoway	Butt of Lewis	1743 kHz	07:10 and 19:10
Falmouth	Scillies	1880 kHz	07:10 and 19:10
Aberdeen	Gregness	2226 kHz	07:30 and 19:30
Humber	Cullercoats	1925 kHz	07:50 and 19:50

Table 4 - MF RT MSI Schedule

Note: Transmissions may be repeated 6 hours after initial scheduled broadcast if new Gale or Storm warnings have been issued.

Figure 4 - Coastal Warning and Inshore Waters Areas. © Crown Copyright 2024. All rights reserved. Reproduced from Admiralty List of Radio Signals (ALRS), UK Hydrographic Office. NOT TO BE USED FOR NAVIGATION.

9.  VHF and MF RT Schedule, Routine A.

9.1 Full MSI broadcasts are made every 12 hours in the morning and in the evening as described in the schedule below (see Tables 5). They contain information pertinent to the areas covered by the broadcasting coastal radio station (see Table 6 and Table 7) and include, where appropriate:

• Gale Warnings (Gale Force 8 and above, including Storm Force 10 +)
• New Inshore Waters Forecast and Outlook
• New Shipping Forecast
• All in force Navigation Warnings
• Three-Day Fisherman’s Forecast (Between October and March from designated stations – see Table 8)
• Local Navigation Warnings
• Submarine and Gunnery Exercises (SUB and GUN FACTS)

10.  VHF (only) RT Schedule, Routine B

10.1 Short MSI broadcasts are made every 3 hours as described in the schedule below (see Table 5). They either contain new or a repetition of information previously broadcast. Information provided will be pertinent to the areas covered by the broadcasting coastal radio station and include (where appropriate):

• Gale Warnings (Gale Force 8 and above, including Storm Force 10 +)
• Inshore Waters Forecasts and Outlook
• NEW Navigational Warnings
• Local Navigation Warnings

10.2 Table 6 and Table 7 provide details of forecasts that are broadcast by each MRCC.

10.3 The provision of information outlined above and in the tables below is subject to frequency availability and maybe interrupted or delayed in the event of ongoing Search and Rescue working.

MRCC	SCHEDULE ROUTINE A (LOCAL TIME)	SCHEDULE ROUTINE B (LOCAL TIME)	BROADCAST AERIALS	VHF CHANNEL
Aberdeen Coastguard	07:30 and 19:30	01:30, 04:30, 10:30, 13:30*, 16:30 and 22:30	Durness	63
			Noss Head	62
			Rosemarkie	64
			Windy Head	63
			Gregness	64
			Inverbervie	63
			Fifeness	62
			Craigkelly	63
			St Abbs head	64
Belfast Coastguard	08:10 and 20:10	02:10, 05:10, 11:10, 14:10*, 17:10 and 2310	Limivady	10
			West Torr	64
			Black-Mountain	63
			Orlock	62
			Loughnavar	64
			Slieve Martin	64
			Greenock	62
			Law hill	64
			Rhu Staffnish	10
			Kilchiaran	62
			South-Knapdale	63
Dover Coastguard	07:10 and 19:10	01:10, 04:10, 10:10, 13:10*, 16:10 and 22:10	Bawdsey	62
			Walton	63
			Bradwell	64
			Shoeburyness	63
			Langdon	64
			Fairlight	62
Falmouth Coastguard	07:10 and 19:10	01:10, 04:10, 10:10, 13:10*, 16:10 and 22:10	Berry Head	63
			Dartmouth	10
			Prawle	62
			Rame Head	64
			Fowey	10
			Falmouth	62
			Lizard	63
			Scillies 64
			Trevose	62
Holyhead Coastguard	07:30 and 19:30	01:30, 04:30, 10:30, 13:30*, 16:30 and 22:30	Great Orme	62
			South Stack	63
			Moel-Y-Parc	63
			Calbeck	63
			Langthwaite	62
			Snaefell	64
Humber Coastguard	07:50 and 19:50	01:50, 04:50, 10:50, 13:50*, 16:50 and 2250	Newton	63
			Cullercoats	64
			Boulby	63
			Ravenscar	64
			Flamborough	63
			Easington	64
			Mablethorpe	62
			Guy’s head	63
			Langham	64
			Trimingham	63
			Caister	64
			Lowestoft	63
Milford Haven Coastguard	07:50 and 19:50	01:50, 04:50, 10:50, 13:50*, 16:50 and 2250	Hartland 64
			Combe Martin	63
			Severn	64
			St Hilary	63
			Mumbles	64
			Tenby	62
			St Anns	62
			Dinas	64
			Blaenplwyf	62
Shetland Coastguard	07:10 and 19:10	01:10, 04:10, 10:10, 13:10*, 16:10 and 22:10	Saxavord	63
			Collafirth	64
			Shetland	62
			Fitful 63
			Wideford	64
Solent Coastguard	07:30 and 19:30	01:30, 04:30, 10:30, 13:30*, 16:30 and 22:30	Newhaven	62
			Boniface 63
			Needles	62
			Portland	63
			Beer Head	62
Stornoway Coastguard	07:10 and 19:10	01:10, 04:10, 10:10, 13:10*, 16:10 and 22:10	Torasay	10
			Tiree	63
			Glengorm	62
			Arisaig	64
			Barra	10
			Drumfearn	63
			Skriag	10
			Clettraval	63
			Rodel	62
			Melvaig	64
			Forsnaval	62
			Portnaguran	63
			Butt of Lewis	10

Table 5 – MRCC VHF MSI Broadcast Schedule

• New Inshore Waters Forecast and New Gale Warnings.

AREA NO.	NAVIGATION WARNING AND INSHORE WATERS FORECAST AREAS	BROADCAST BY
1	Cape Wrath to Rattray Head, including Orkney	Shetland Coastguard, Aberdeen Coastguard
2	Rattray Head to Berwick-upon-Tweed	Aberdeen Coastguard
3	Berwick-upon-Tweed to Whitby	Humber Coastguard
4	Whitby to Gibraltar Point	Humber Coastguard
5	Gibraltar Point to North Foreland	Humber Coastguard, Dover Coastguard
6	North Foreland to Selsey Bill	Dover Coastguard, Solent Coastguard
7	Selsey Bill to Lyme Regis	Solent Coastguard
8	Lyme Regis to Land’s End, including the Isles of Scilly	Solent Coastguard, Falmouth Coastguard
9	Land’s End to St David’s Head, including the Bristol Channel	Falmouth Coastguard, Milford Haven Coastguard
10	St David’s Head to Great Orme’s Head, Including St George’s Channel	Milford Haven Coastguard, Holyhead Coastguard
11	Great Orme’s Head to the Mull of Galloway	Holyhead Coastguard
12	Isle of Man	Holyhead Coastguard, Belfast Coastguard
13	Lough Foyle to Carlingford Lough	Belfast Coastguard
14	Mull of Galloway to Mull of Kintyre including the Firth of Clyde and North Channel	Belfast Coastguard
15	Mull of Kintyre to Ardnamurchan Point	Belfast Coastguard, Stornoway Coastguard
16	The Minch	Stornoway Coastguard
17	Ardnamurchan Point to Cape Wrath	Stornoway Coastguard
18	Shetland Isles and 60 nautical mile radius	Shetland Coastguard
19	Channel Islands	Jersey Coastguard

Table 6 - Navigation Warning and Inshore Waters Forecast Broadcast Area by RCC (see Figure 4)

SHIPPING FORECAST AREAS	BROADCAST BY
Viking	Shetland Coastguard
Forties	Aberdeen Coastguard
Cromerty	Aberdeen Coastguard, Shetland Coastguard
Forth	Aberdeen Coastguard
Tyne	Aberdeen Coastguard, Humber Coastguard
Dogger	Humber Coastguard
Fisher	Humber Coastguard
German Bight	Humber Coastguard
Humber	Dover Coastguard, Humber Coastguard
Thames	Dover Coastguard, Humber Coastguard
Dover	Dover Coastguard, Solent Coastguard
Wight	Dover Coastguard, Solent Coastguard
Portland	Falmouth Coastguard, Solent Coastguard
Plymouth	Falmouth Coastguard, Solent Coastguard
Fitzroy	Falmouth Coastguard
Sole	Falmouth Coastguard
Lundy	Falmouth Coastguard, Milford Haven Coastguard
Fastnet	Falmouth Coastguard, Milford Haven Coastguard
Irish Sea	Belfast Coastguard, Holyhead Coastguard, Milford Haven Coastguard
Shannon	Milford Haven Coastguard
Rockall	Belfast Coastguard, Stornoway Coastguard
Malin	Belfast Coastguard, Stornoway Coastguard
Hebrides	Belfast Coastguard, Stornoway Coastguard
Bailey	Stornoway Coastguard
Fair Isle	Aberdeen Coastguard, Shetland Coastguard, Stornoway Coastguard
Faroes	Shetland Coastguard, Stornoway Coastguard
Southeast Iceland	Stornoway Coastguard

Table 7 - Shipping Forecast Areas Covered by MRCC (see Figure 2)

MRCC	​Fishing Fleet Forecast Coverage
​Shetland Coastguard	Northern North Sea including Sea Areas: Fair Isle, Viking, Cromarty and Forties
Aberdeen Coastguard	Northern North Sea including Sea Areas: Viking, Cromarty, Forth, Forties, Fisher, Tyne and Fair Isle
Humber Coastguard	Southern North Sea including Sea Areas: Tyne Dogger, German Bight, Humber and Thames
Falmouth Coastguard	Southwestern Approaches including Sea Areas: Plymouth, Fastnet, Shannon, Sole and Fitzroy
Stornoway Coastguard	Western Isles and Northwestern Approaches: Malin, Hebrides, Rockall, Faeroes

Table 8 - Fishing Fleet Broadcasting Stations - Routine A

More information

UK Technical Services Navigation Branch
Maritime and Coastguard Agency
Bay 2/25
Spring Place
105 Commercial Road
Southampton
SO15 1EG

Telephone: +44 (0)203 81 72000

Email: msi_mca@mcga.gov.uk

Website: www.gov.uk/mca

General enquiries: infoline@mcga.gov.uk