For commercial vessels, accurate and up-to-date nautical charts are an essential part of safe navigation and regulatory compliance. Under the International Convention for the Safety of Life at Sea (SOLAS), ships are required to carry appropriate nautical charts and publications for their intended voyage.
For vessel owners, operators, masters and navigating officers, understanding SOLAS chart requirements is important not only for meeting international regulations but also for ensuring that the vessel can safely plan, monitor and execute its voyage.
This guide explains the key SOLAS requirements for nautical charts, including the role of Electronic Chart Display and Information Systems (ECDIS), electronic navigational charts (ENCs), updates and backup arrangements.
What Are the SOLAS Chart Requirements?
SOLAS Chapter V deals with Safety of Navigation. Regulation V/27 requires ships to carry adequate and up-to-date charts and nautical publications appropriate for the intended voyage.
The International Maritime Organization (IMO) states that nautical charts and publications must enable the vessel to plan and display its intended route and to plot and monitor its position throughout the voyage.
For commercial vessels, this means that having charts on board is not simply a matter of carrying a chart portfolio. The charts must be:
- Appropriate for the vessel’s intended area of operation
- Suitable for voyage planning and navigation
- Corrected and kept up to date
- Available for the areas through which the vessel will navigate
- Supported by appropriate backup arrangements where electronic navigation is used
South African maritime operators should also consider applicable South African Maritime Safety Authority (SAMSA) requirements in addition to international SOLAS obligations. SAMSA inspection guidance specifically notes that charts for the vessel’s area of operation must be corrected and up to date.
Paper Charts or ECDIS?
One of the biggest changes to commercial navigation has been the transition from traditional paper charts to electronic navigation.
SOLAS permits an approved ECDIS to satisfy the chart carriage requirements when the equipment and arrangements comply with the applicable requirements. IMO explains that ECDIS was incorporated into SOLAS as an accepted means of meeting chart carriage requirements, with mandatory carriage subsequently phased in for applicable ships.
ECDIS is a computer-based navigation system that uses electronic navigational charts and positioning information to assist with route planning and route monitoring.
For an ECDIS arrangement to replace paper charts for SOLAS purposes, the system must meet the applicable IMO performance standards and have appropriate backup arrangements.
What Is an ENC?
An Electronic Navigational Chart (ENC) is an official digital navigational chart produced under the authority of a government-authorised hydrographic office.
ENCs provide the chart data displayed by a compliant ECDIS. They are different from unofficial electronic charts or digital copies of paper charts.
IMO’s ECDIS performance standards specify that electronic navigational charts are standardised databases issued under the authority of government-authorised hydrographic offices. They are intended to provide the information necessary for safe and efficient navigation.
For commercial vessels, using the correct official chart data is therefore an important part of maintaining a compliant navigation system.
ECDIS Carriage Requirements
ECDIS carriage requirements depend on factors such as:
- Vessel type
- Gross tonnage
- Whether the vessel is engaged on international voyages
- Date of construction
- Applicable flag State requirements
- Applicable SOLAS requirements and exemptions
For example, IMO identifies mandatory ECDIS carriage requirements for newly built passenger ships of 500 gross tonnage and upwards and newly built cargo ships of 3,000 gross tonnage and upwards engaged on international voyages, with requirements also phased in for existing ships.
This is why vessel operators should assess their individual vessel rather than assuming that one chart requirement applies to every commercial ship.
Keeping SOLAS Charts Up to Date
Carrying the correct charts is only part of compliance. Charts and electronic chart data must also be maintained and updated.
SOLAS requires nautical charts and publications to be adequate and up to date.
For paper charts, this generally involves applying the appropriate corrections and Notices to Mariners.
For ECDIS, operators need to ensure that:
- Official ENC data is used
- ENC updates are applied correctly
- The ECDIS software is appropriately maintained
- The latest applicable chart information is available
- The system is operated in accordance with its approval and manufacturer’s requirements
- Updates are checked and incorporated into the vessel’s navigation procedures
IMO guidance specifically highlights the importance of onboard ECDIS updates, software maintenance and the safe operation of ECDIS.
Why ECDIS Updates Matter
An electronic chart is not automatically compliant simply because it is installed on an ECDIS.
Navigation information can change because of:
- New or amended navigational hazards
- Changes to buoyage
- New or altered navigation aids
- Changes to channels and traffic separation schemes
- Port developments
- Depth information
- Temporary navigation warnings
- Other corrections issued by the relevant authorities
Failure to incorporate relevant updates can result in a vessel navigating using outdated information.
For this reason, chart management should form part of the vessel’s documented navigation and safety procedures.
ECDIS Backup Requirements
Backup arrangements are an important part of SOLAS-compliant electronic navigation.
IMO’s ECDIS performance standards recognise that ECDIS may meet the requirement for up-to-date charts when appropriate backup arrangements are provided.
Depending on the vessel’s approved configuration and applicable requirements, backup arrangements may include an appropriate second ECDIS or an approved portfolio of paper nautical charts.
The backup arrangement must be suitable for allowing safe navigation if the primary ECDIS becomes unavailable.
Operators should therefore avoid treating backup charts as an afterthought. The arrangement should be considered as part of the vessel’s overall navigation system and procedures.
What Other Nautical Publications May Be Required?
SOLAS chart carriage requirements extend beyond the chart itself.
Depending on the vessel and voyage, navigational publications can include information such as:
- Sailing directions
- Lists of lights
- Tide tables
- Notices to Mariners
- Nautical almanacs
- Radio or communication-related navigational information
- Other publications necessary for safe navigation
IMO notes that governments are responsible for providing hydrographic and nautical information, including nautical charts, sailing directions, lists of lights, tide tables and other nautical publications where applicable.
The precise publications required will depend on the vessel, its route and applicable flag State and port State requirements.
SOLAS Chart Compliance Checklist
Before sailing, commercial vessel operators should consider whether:
- The charts cover the entire intended voyage
- The charts are suitable for the vessel’s navigation requirements
- Paper charts are correctly corrected where applicable
- ENCs are official and appropriate for the voyage
- ENC updates have been applied
- The ECDIS is operating correctly
- ECDIS software is appropriately maintained
- Required nautical publications are available
- Required backup arrangements are in place
- Officers using ECDIS have the appropriate training
- Voyage plans have been prepared using the current navigational information
- Relevant Notices to Mariners and other navigational warnings have been considered
A robust chart management process can help reduce the risk of navigation errors while supporting compliance during inspections and audits.
New ECDIS Standards and S-100
Electronic navigation continues to evolve.
IMO has adopted revised ECDIS performance standards introducing a phased implementation of new International Hydrographic Organization (IHO) product specifications, including S-98, S-100 and S-101. According to IMO, the revised standards apply to new ECDIS installations on a phased basis, with the transition beginning in 2026 and mandatory application for all new ECDIS installations from 1 January 2029.
This development is significant for vessel operators planning ECDIS upgrades or new-build installations.
Shipowners and operators should therefore consider not only today’s requirements but also the future compatibility and lifecycle of their navigation systems.
SOLAS Charts and Commercial Vessel Safety
Chart compliance is ultimately about much more than satisfying an inspection requirement. Accurate navigational information is fundamental to safe voyage planning and the prevention of incidents such as grounding, collision and navigation errors.
SOLAS Chapter V establishes the international framework for safety of navigation, while flag States and maritime authorities may impose additional requirements.
For vessels operating from or within South African waters, operators should ensure that their navigation arrangements meet applicable SOLAS, SAMSA, flag State and port State requirements.
Need Help With Commercial Vessel Chart Requirements?
Ensuring that your vessel has the correct charts, publications, updates and navigation arrangements can be a complex part of commercial vessel compliance.
Tyneside can assist maritime operators with professional nautical chart and navigation requirements, helping ensure that vessels have the information they need for safe and compliant operations.
Contact Tyneside to discuss your vessel’s SOLAS chart requirements, nautical charts, ECDIS and commercial maritime navigation needs.
Frequently Asked Questions
Are commercial vessels required to carry nautical charts under SOLAS?
Yes. SOLAS Chapter V requires ships to carry adequate and up-to-date charts and nautical publications appropriate for their intended voyage.
Can ECDIS replace paper charts?
An approved ECDIS can satisfy SOLAS chart carriage requirements when it complies with the applicable IMO performance standards and appropriate backup arrangements are provided.
Do ECDIS charts need to be updated?
Yes. Nautical chart information must be kept up to date. For ECDIS, this includes maintaining appropriate official ENC data and applying relevant updates.
What is an ENC?
An ENC is an official electronic navigational chart database issued under the authority of a government-authorised hydrographic office for use with ECDIS.
Does SOLAS apply to all commercial vessels in the same way?
No. Requirements can vary according to vessel type, size, construction date, voyage type, flag State requirements and other applicable regulations.
Are paper charts still relevant?
They can be. Depending on the vessel’s approved navigation arrangement and applicable requirements, paper charts may form part of the primary or backup navigation arrangement.
Conclusion
Understanding SOLAS chart requirements for commercial vessels is essential for safe navigation and regulatory compliance. Whether a vessel operates with paper charts, ECDIS or a combination of approved systems, navigational information must be appropriate for the voyage, accurate and kept up to date.
With ECDIS technology and electronic chart standards continuing to evolve, vessel operators should regularly review their chart management procedures and navigation equipment to ensure ongoing compliance.
Contact us today to learn more.
The Tyneside is proudly designated as the appointed distributor for the British Admiralty and South African Navy Hydrographic Office in South Africa. In addition to this esteemed role, we serve as the official distributor for the International Maritime Organisation (IMO) and the International Telecommunications Union (ITU).