Admiralty Guide on the Practical Use of ENC (NP231), 3rd Edition 2019

ractical Use of ENC NP231

The purpose of this publication is to help seafarers acquire and maintain a high level of knowledge about the content and use of ECDIS ENCs. It is intended to supplement and enhance the elements of ECDIS training on the use and interpretation of chart data. This does not replace the training requirements set out in the International Maritime Organization (IMO) Model Course 1.27 or the STCW Manila Amendment.

Navigation using ECDIS is fundamentally different from navigation using paper charts. ECDIS provides navigators with a very flexible display. This greatly improves situational awareness and safety when properly configured. Watchkeepers need to give more time to maintain a proper visual watch. However, if the display and ECDIS settings are not fully understood, the chart display can be misinterpreted and, in the worst case, compromise the safety of the vessel.

The computer-based training package was developed by the UK Hydrographic Office to help ENC users move to digital navigation. It is designed to give you a deeper understanding of the ENC and ECDIS display and supports the ENC-related knowledge gained during general type-specific training. You can also update your knowledge or use it as a reference. Upon successful completion, it will be marked with an official certificate.

The CD must be inserted in the drive at the time of use. It is designed to work with the following operating systems:

Microsoft Windows XP, Windows Vista, Windows 7, and the following browsers:

Internet Explorer 6, 7, 8, 9. You also need the Adobe Flash Player included on the disc.

In addition to the paper format and NP70, this publication is available as ADMIRALTY e-Nautical Publication (AENP). AENP improves the efficiency, accuracy, and access to the information bridge crews need through electronic NM updates and simple search capabilities. (Note: Admiralty e-NPs are not downloaded directly from the site. All e-NPs must be assigned after purchase.)

Course purpose:

A one-day course that gives participants a complete understanding of the interactions between ENC data, NP70 software, and ECDIS users.

Who will benefit:

This course is primarily intended for nationally certified maritime instructors or industry training professionals (training managers, supervisors, etc.). It may also be useful for personnel who perform monitoring or evaluation functions (such as VTS operators, port managers, port and flag state assessors), or who provide relevant services such as pilots and tugboat masters. Not designed for direct training of bridge observers. Participants must be pre-attended in the ECDIS Operator STCW Course, which is accredited to the IMO Model Course 1.27 or equivalent  standards.



The following important topics are considered.

• Building an NP70 and its impact on its use in ECDIS systems

• Display NP70 data

• Display Settings: Understand the importance of navigation-critical settings and how operators can change them.

• ENC accuracy: Understand the quality of the data displayed in ENC and how to check the reliability of its accuracy.

• ENC loading and updating: a successful way to maintain charts, including supply and support services

• ENC-based voyage planning: impact on ENC-based voyage planning, including evaluation, planning, execution, and monitoring.

• Procedure considerations when using ENC: Incorporate ENC-related issues into the bridging procedure.


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