Report from 52nd session of IMO Safety of Navigation Sub-committee (NAV 52)

Last week INTERTANKO attended the 52nd session of the IMO’s Safety of Navigation Sub-committee (NAV 52). The Sub-committee’s agenda contained several proposals for new Traffic Separation Schemes (TSS) and amendments to existing ones, as well as a proposal for a new “emergency wreck marking buoy”, developed by the International Association of Lighthouse Authorities (IALA).  

The Sub-committee also amended the performance standards for Electronic Chart Display and Information Systems (ECDIS), revised the performance standards for Inertial Navigation Systems (INS)/Intelligent Bridge Systems (IBS) and evaluated the use of ECDIS and Electronic Navigation Chart (ENC) development.  

Traffic Separation Schemes 

New and amendments to existing Traffic Separation Schemes (TSSs), subject to adoption by MSC 82 in Nov/Dec 2006.  

Norway: New TSSs and recommended routes off the coast of Norway from Vardø to Røst. The proposal consists of eight new TSSs and seven recommended routes connecting them, off the coast of Norway. The new TSSs will be mandatory for vessels carrying hazardous cargo. The Committee believed that the new schemes and recommended routes are not likely to cause a disproportionate burden to the shipping industry, and the proposal was also supported by INTERTANKO. 

United Kingdom: Various new TSSs and amendments to existing TSSs in the U.K. A new TSS in the SUNK area and associated routeing measures in the Northern approaches to the Thames Estuary and in the Minches off Neist Point.

Amendments to the existing deep-water route west of the Hebrides, and recommended routes in the Minch. 

United States: Amendments to the existing TSS in the approach to Boston. The reason for this is that the existing shipping lanes are established in a very right-whale dense area, and in order to save these species from ship strikes, the TSS will be slightly moved. The depth of water is very important for the right-whales and the existing TSS is running through an area where the right-whales have one of their most important food-grounds. With the amendments, ship strikes of whales will be less likely and shipping will therefore present less threat to this mammal, whose numbers are dwindling. INTERTANKO supported the proposal. 

Tunisia: The existing TSSs “Off Cani Island” and “Off Cape Bon” will be slightly moved outwards (North) to increase the protection of the environment in an event of a ship disaster.  

The English Channel: Various minor changes and amendments to the existing TSS and abolition of the area to be avoided around the EC 2 Light buoy. 

Adriatic Sea: Various amendments to the TSS in the Adriatic Sea and the establishment of an area to be avoided in the approaches to Venice. 

New Zealand: A precaution area to be established off the west coast of the North Island of New Zealand. 

Strait of Gibraltar: In order to establish safe routeing measures for traffic bound to or from the port of Tanger-Med, various amendments to the existing TSS and the inshore traffic zone have been proposed. A precautionary area is also to be amended. 

Ship Reporting Systems

Establishment of new and amendments to existing Ship Reporting Systems (SRS), subject to adoption by MSC 82 in Nov/Dec 2006.  

Galapagos Islands: A new mandatory SRS, GALREP, for the Galapagos Area to be Avoided and Particularly Sensitive Sea Area (PSSA) would enable the Maritime Rescue Sub-Centre located in the Galapagos to obtain accurate information on these ships and issue an alert promptly to ensure an immediate response, if necessary. 

Great Belt Traffic Area: Proposal for an expansion of the existing mandatory SRS. 

Gulf of Finland: Amendments to the existing mandatory SRS, in order to facilitate accurate information to and from ships, especially in ice conditions.

Revision of the performance standards for INS/IBS 

The Sub-Committee established a working group, with the terms of reference to develop draft revised performance standards for Inertial Navigation Systems (INS) including an alert management module, draft revised Intelligent Bridge System (IBS) performance standards together with Bridge Resource Management (BRM) Guidelines to allow for a comprehensive application of SOLAS Regulation V/15 (Principles relating to bridge design, design and arrangement of navigational systems and equipment and bridge procedures).

The working group will submit its report to NAV 53 (June 2007). 

Amendments to the ECDIS performance standards 

The Sub-Committee agreed with a proposal from the technical working group, regarding amendments to the ECDIS performance standards. The draft amendments were forwarded to MSC 82 for adoption. Click here for a copy of the draft. The wording covering the back-up requirements in the draft is as follows: 


“As prescribed in section 14 of this performance standard, adequate independent back-up arrangements should be provided to ensure safe navigation in case of ECDIS failure. Such arrangements include: 

Facilities enabling a safe take-over of the ECDIS functions in order to ensure that an ECDIS failure does not result in a critical situation;

a means to provide for safe navigation for the remaining part of the voyage in case of ECDIS failure.”


The Sub-committee furthermore agreed to issue a Safety of Navigation (SN) Circular and were invited to bring this guidance to the attention of all concerned for information and action, as appropriate. The SN Circular has not yet been finalised and released by the IMO, but click here for the context of the Circular (Additional guidance on chart data and the accuracy of positions on charts).

Evaluation of the use of ECDIS and Enc development 

The Sub-committee discussed the carriage requirements of ECDIS. Some delegations were of the opinion that the necessary ENCs will not be available until the carriage requirements are in place; others were of the opinion that the carriage requirements cannot be implemented until the coverage of the ENCs is fully available. A majority of the delegations were of the view that ENC coverage was a necessary prerequisite for the introduction of a mandatory carriage requirement of ECDIS. Some delegations were of the view that this did not mean that a 100% coverage would be necessary or achievable. The International Hydrographic Organization (IHO) was invited to provide more information on the status of ENC coverage to NAV 53 (June 2007), and the Sub-committee reiterated its invitation to the IHO and MemberStates to continue progress towards ENC developments.

Emergency wreck marking buoy

The Sub-committee agreed with a proposal by the International Association of Lighthouse Authorities (IALA) that in addition to existing buoys, a special buoy called an “emergency wreck marking buoy” would be beneficial. The new buoy is designed to provide high visual and radio aid to navigation recognition. The buoy would have the following characteristics: 

Ø       a pillar or spare buoy;

Ø       blue and yellow stripes (minimum 4 / maximum 8);

Ø       alternating blue/yellow flashing light, where the blue and yellow 1 second flashes are alternated with an interval of 0.5 seconds. 

The new buoy will be submitted for adoption at MSC 82. 

AIS – accuracy of transmissions 

The U.K. informed the Sub-committee that it is actively carrying out surveillance of Automatic Identification Systems (AIS) along its coast, with the aim of identifying and informing ship operators of erroneous vessel data being transmitted in U.K. waters. Vessels transmitting such information will be called by means of VHF/HF and urged to correct their transmissions. Vessels that fail to correct their erroneous transmissions may be reported to the appropriate Port State Control (PSC) authority. 

INTERTANKO members should note that whenever the word draft is used in this report, the subject has not yet been adopted by the IMO.  

Contact: Fredrik Larsson