Introduction
We as navigating officers must always aim at safe navigation. Navigational warnings are among those tools to inform mariners of any event concerning the navigational safety of ships. Navigational warnings provide early information of important incidents which may constitute a danger to navigation. Many navigational warnings are of a temporary nature, but others remain in force for several weeks and may be succeeded by notices to mariners.
Solas Regulations w.r.t Navigational Warnings
Regulation 4
Navigational warnings
Each Contracting Government shall take all steps necessary to ensure that, when intelligence of any dangers is received from whatever reliable source, it shall be promptly brought to the knowledge of those concerned and communicated to other interested Governments.
Regulation 5
Meteorological services and warning
1) Contracting Governments undertake to encourage the collection of meteorological data by ships at sea and to arrange for their examination, dissemination and exchange in the manner most suitable for the purpose of aiding navigation.* Administrations shall encourage the use of meteorological
instruments of a high degree of accuracy, and shall facilitate the checking of such instruments upon request. Arrangements may be made by appropriate national meteorological services for this checking to be undertaken, free of charge to the ship.
2) In particular, Contracting Governments undertake to carry out, in co-operation, the following meteorological arrangements:
i) to warn ships of gales, storms and tropical cyclones by the issue of information in text and, as far as practicable graphic form, using the appropriate shore based facilities for terrestrial and space radiocommuniaction services. ii) to issue, at least twice daily, by terrestrial and space radiocommunication services*, as appropriate, weather information suitable for shipping containing data, analyses, warnings and forecasts of weather, waves and ice. Such information shall be transmitted in text and, as far as practicable, graphic form including meteorological analysis and prognosis charts transmitted by facsimile or in digital form for reconstitution on board the ship’s data processing system.
iii) to prepare and issue such publications as may be necessary for the efficient conduct of meteorological work at sea and to arrange, if practicable, for the publication and making available of daily weather charts for the information of departing ships.
iv) to arrange for a selection of ships to be equipped with tested marine meteorological instruments (such as a barometer, a barograph, a psychrometer, and suitable apparatus for measuring sea temperature) for use in this service, and to take, record and transmit meteorological observations at the main standard times for surface synoptic observations (i.e. at least four times daily, whenever circumstances permit) and to encourage other ships to take, record and transmit observations in a modified form, particularly when in areas where shipping is sparse.
v) to encourage companies to involve as many of their ships as practicable in the making and recording of weather observations; these observations to be transmitted using the ship’s terrestrial or space radiocommunications facilities for the benefit of the various national meteorological services.
vi) the transmission of these weather observations is free of charge to the ships concerned.
vii)when in the vicinity of a tropical cyclone, or of a suspected tropical cyclone, ships should be encouraged to take and transmit their observations at more frequent intervals whenever practicable, bearing in mind navigational preoccupations of ships’ officers during storm conditions.
viii) to arrange for the reception and transmission of weather messages from and to ships, using the appropriate shore-based facilities for terrestrial and space radiocommunications services.
ix) to encourage masters to inform ships in the vicinity and also shore stations whenever they experience a wind speed of 50 knots or more (force 10 on the Beaufort scale).
x) to endeavour to obtain a uniform procedure in regard to the international meteorological services already specified, and as far as practicable, to conform to the technical regulations and recommendations made by the World Meteorological Organization, to which Contracting Governments may refer, for study and advice, any meteorological question which may arise in carrying out the present Convention.
xi) The information provided for in this regulation shall be furnished in a form for transmission and be transmitted in the order of priority prescribed by the Radio Regulations. During transmission “to all stations” of meteorological information, forecasts and warnings, all ship stations must conform to the provisions of the Radio Regulations.397
xii)Forecasts, warnings, synoptic and other meteorological data intended for ships shall be issued and disseminated by the national meteorological service in the best position to serve various coastal and high seas areas, in accordance with mutual arrangements made by Contracting Governments, in particular as defined by the World Meteorological Organization’s System for the Preparation and Dissemination of Meteorological Forecasts and Warnings for the High Seas under the Global Maritime Distress and Safety System.
WWNWS
The World-Wide Navigational Warning Service (WWNWS) is a co-ordinated global service for the promulgation of navigational warnings. WWNWS is established through the joint efforts of the International Hydrographic Organization (IHO) and the International Maritime Organization (IMO). These navigational warnings form part of the Maritime Safety Information broadcasted via Navtex and SafetyNET.
Navigational warnings are of three types:
- NAVAREA warnings,
- Coastal warnings,
- Local warnings.
Under this system the world’s oceans are divided into 21 areas, called NAVAREAs and identified by Roman numerals. WMO uses the same areas for their meterological warnings.
India comes under NAVAREA 8
https://iho.int/navigation-warnings-on-the-web
The above mentioned link further provides links for NAVAREA Coordinators’ website where Navigational Warnings are listed.
Types of Navigational Warnings
Navigational warnings are mainly of the following types-
• Casualties to large navigational buoys, primary lights or lightships.
• Changes in depth of water
• Dangerous wrecks or obstruction to navigation
• Floating dangers-like containers, drifting buoys, icebergs
• Newly established aids to navigation
• Gunnery or fire exercise areas and underwater activities in certain areas
• Vessels aground in approaching port areas
• Any changes or development of new buoyage system
• Gale warnings
Difference between Navareas and Metareas
For meteorological warnings each Navarea is further divided into Metareas.
METAREAs are usually divided into sea areas for weather forecast broadcast using INMARSAT-C (EGC), NAVTEX, VHF, MF and HF radio
Sources of Navigational Warnings
Navigational warnings can be received through Navtex and EGC,
There are three sources from where we can get EGC warnings onboard. Sat-C, chart management software and from the website of the Navarea co-ordinator.
What is Maritime Safety Information (MSI)
The Maritime Safety Information (MSI) service is an internationally co-ordinated network of broadcasts of Maritime Safety Information. This information contains:
- Navigational warnings;
- Meterological information (forecasts and warnings);
- Distress alerts.
MSI is part of the Global Maritme Distress and Safety System (GMDSS). Every ship, while at sea, has to be capable of transmitting and receiving maritime safety information. Reception of MSI is free of charge to all ships.
MSI is transmitted by a variety of means, using terrestrial and satellite radiocommunications. The GMDSS supports two independent systems to broadcast Maritime Safety Information (MSI):
- NAVTEX, MF terrestrial radio to cover many coastal areas.
- SafetyNET, using the Inmarsat-C Enhanced Group Call (EGC), covering the entire Inmarsat ocean regions including costal areas.
To ensure that the ships know when to receive MSI for a given area and subject, many of the MSI broadcasts are scheduled, under IMO co-ordination, to a particular time, Land Earth Station and Ocean Region.
All navigational warnings and meteorological forecasts are scheduled broadcasts with a safety priority, which does not produce an alarm at the receiver. Meteorological warnings and shore-to-ship distress alerts are unscheduled broadcasts with urgency or distress priority (broadcast on receipt), which does produce an alarm at the receiver.
Transmission of Maritime Safety Information from ship-to-shore is also possible. This may be accomplished using any transmission means available to the ship. Normally, Digital Selective Calling on MF/HF or VHF will be used or one of the Inmarsat services. Inmarsat has special 2-digit codes defined for this purpose.
What is EGC (Enhanced Group Call)
Enhanced Group Call (EGC) service is a part of the GMDSS system for the transmission of maritime safety information (MSI) in areas where the NAVTEX service is not available. These messages could be e.g. Navigational warnings, Meteorological warnings, Meteorological forecasts and Search And Rescue messages.
The EGC service uses the Inmarsat C system for broadcasting these messages. The Enhanced Group Call (EGC) service is used for the transmission of messages to a group of ships or to ships in a specified area via the Inmarsat satellites.
For the reception of EGC messages an Inmarsat C terminal will be used. A printer will be connected to this terminal for printing the received messages. These messages will also be stored in a log file on the terminal and can be displayed on the terminal screen.
In-force list of warnings can be received from SAT C every week.
The EGC messages can be divided into two categories known as:
- SafetyNET and
- FleetNET.
What is SafetyNet
SafetyNET is an international automatic direct-printing satellite-based service for the promulgation of Maritime Safety Information (MSI), navigational and meteorological warnings, meteorological forecasts, Search and Rescue (SAR) information and other urgent safety-related messages to ships. It has been developed as a safety service of the Inmarsat C Enhanced Group Call (EGC) system to provide a simple and automated means of receiving MSI on board ships at sea.
The message-selection features of SafetyNET receivers enable mariners to receive safety information broadcasts that are tailored to their particular
needs. As a part of Inmarsat’s GMDSS modernization programme, SafetyNET II was developed by Inmarsat with the support from the wider maritime community in 2017.
Actions on receiving a Navigational Warning
The first thing that an officer of the watch should do on receiving a Navarea caution is to check if it’s going to have an effect on the current voyage. If it falls in the route, it must be plotted with out delay and must be informed to the Master and watchkeeping officers. The warning is marked as “plotted on enc no or chart no” and filed. In case of the paper chart the navigational warning number is also mentioned at the bottom of the chart.
A log is prepared for ENCs where navigational warning numbers are logged against the ENCs number after they are plotted on ENC.
If the caution is out of route, the warning will be marked that it doesn’t fall under the route and filed.
During plotting a Nav warning it is required to keep in mind that the chart shouldn’t be saturated with information which would cause obscuring of other important information.
How to determine that a Navigational warning is within your route?
The answer of this question would depend on the Safety management system adopted by the company. Generally the radius of circle with your route as centre is mentioned within the Safety management system for which the Navigational Warnings received are required to be plotted.
How to know if a Naviational Warning is Cancelled?
Navarea warnings are normally cancelled for 3 reasons:
1)A Navigational warning is superseded by a more recent warning and is consequently cancelled.
2)A Navarea warning self-cancels because it had a hard and fast cancellation date.
3)The Navarea coordinator cancels the message.
The in force listing of warnings may be obtained via SAT C each week from which the officer can decide the notices which are cancelled. Also, we can get to know about cancelled notices through chart management software using the Cancelled view.
IMO encourages Navtex stations to send the in-force list every week Navtex stations have limited time (10 minutes) to transmit the messages. Including in-force list will only reduce the time for actual transmission.
We can download the in-force warnings from the internet (Official sites of the navtex stations) but
- This is highly discouraged by IMO as well as industry experts like Oil majors.
- Not all nav area coordinators have the in force list for navtex posted on the web
Even if navtex stations send the in-force list every week, not all ocean going ships will receive it. Ship will pass the service area of the station in less than one day. So if the ship passes this area on the day other than the day in-force list is sent, they will not receive it.
How to deal with a cancelled Navigational warning?
On receiving the in force list of warnings, the officer of the watch must first identify the cancelled warnings.
The Navarea file must then be updated and the cancelled warnings should be segregated and put in the Cancelled section.
If paper charts are still being used, the cancelled warnings that have been plotted on the charts must be deleted along with the warning number that is written at the bottom of the chart.
Conclusion
The navigational officers prime duty is to appraise all the hazards to ship and it’s crew and plan the action to avoid them. Navigational Warnings are on of the most important tools when it comes enhancing safety of the ship .