Electronic Navigation represents the most striking change in the modern history of sailing. As recent as the turn of the century, navigation primarily relied on paper charts. Planning, executing and monitoring a voyage consumed most of the time and attention of a crew. However, the introduction of modern digital navigational tools automated much of the work and changed the nature of transoceanic travel. As a result, the Electronic Navigational Charts (ENCs) that an Electronic Chart and Display System (ECDIS) relies on have largely replaced paper charts.
Over time, professional navigational officers have grown accustomed to these tools. However, it’s comparatively recent that the law mandated hobbyists and small sailors to use ECDIS and ENCs. Not to mention, new sailors will also need to learn what an ENC is.
Basics of Electronic Navigational Charts
Electronic navigational charts are one of the two key elements of electronic navigation. An ECDIS functions as the hardware, while an ENC contains the dataset of relevant information for a voyage. Together, these two components create a powerful digital navigation solution. However, they bring much more to the table than eliminating paper waste and storage via basic digitization. Using electronic navigational charts together with ECDIS provides a crew with an array of advantages in planning, monitoring, and executing voyages.
Any modern navigational officer is well aware of the power of the ECDIS. It displays hazard warnings and alarms, enables simplified course modification and automatically identifies safe routes. You’ll achieve these things by inputting accurate values into the ECDIS, such as the draft depth of the ship. Then, it automatically combines this input with oceanic data to create an accurate picture of areas where your ship can sail safely.
This is where the ENC comes into play. While you can fill your ECDIS with precise values on your ship, this is useless without accurate oceanic data. Electronic navigational charts provide your ECDIS with the external, journey-specific data to function properly.
What is an Electronic Navigational Chart (ENC)?
Electronic Navigational Charts (ENC), also known as vector charts, are data sets to support all types of nautical navigation. Originally, large commercial vessels adopted them for the sake of SOLAS compliance, efficiency, and safety benefits. In the modern nautical landscape, smaller ships and recreational sailors also make use of ENCs in electronic chart system (ECS) programs. Electronic navigational charts are the main type of charts that an ECDIS relies on, although there are others, such as Raster Charts.
In their complementary role to ECDIS hardware, an ENC provides a diverse array of information and automation features. These include, but are not limited to:
- Possible dangers
- Maritime limits
- Aids to navigation
- Nature of the seabed
- Configuration and characteristics of the coast
Vector charts enable sailors to create customized displays, depth alerts and more via a the ECDIS. The user can gain a broader visualization by collapsing elements, or access more detailed information about an area by selecting it. These quality of life features make navigation a much simpler, less strenuous process. As a result, electronic navigational charts are entirely indispensable to the modern sailor.
Electronic Navigational Chart Requirements and Standards
Official ENCs must follow several international legal standards. The 1974 IMO SOLAS Convention lays down the basic regulatory framework for using ENCs and ECDIS. Since then, numerous International Maritime Organization (IMO) Resolutions have created a more thorough set of performance standards. As the capabilities and importance of electronic navigation grew over the years, the International Hydrographic Organization (IHO) also developed further detailed standards on ENCs in several publications.
The IMO SOLAS Convention
Regulation 2 provides a legal definition of vector charts. On the other hand, Regulation 19 describes carriage requirements for shipborne navigational systems and equipment. In doing so, it specifies that ECDIS will allow shipowners to meet the chart carriage requirement. This meant that a ship that uses ECDIS could use it to the exclusion of traditional paper charts. Additionally, it imposes an obligation for all vessels regardless of the size and type to carry up-to-date nautical charts and publications for the intended voyage.
Regulation 19 also requires that ships must rely on ENCs to prepare, plot and check the intended route for the voyage. Finally, all vessels that make (even partial) use of ENCs must carry alternative backup arrangements. These can be digitized Raster Charts, a second ECDIS system or paper charts. Regulation 27 imposes a requirement for crews to keep charts and publications up to date.
However, these requirements did not come into effect overnight. Practical implementation took place in a phased manner over one and a half decades. Today, however, all shipowners must install ECDIS before August 2017. The consequences for non-compliance are severe; a flag state inspection could result in financial penalties or detainment.
The IMO has put forward performance standards for ECDIS and vector charts in many Resolutions. Particularly, IMO Resolution A.817 (19) as amended by Resolution MSC.64 (67) regulates backup arrangements. These resolutions require contingencies to remain in place, Should there be a technical failure that prevents the crew from using their ENCs.