What is the International Long Navigation Course (ILNC)?


The International Long Navigation Course (ILNC) is offered, via International Defence Training (Royal Navy) (IDT(RN)), to overseas military students looking to participate in RN Warfare Officer training.

What is the Aim of the Course?

To qualify officers as navigation specialists prior to appointment to ocean-going vessels of frigate size and above and to act as a Navigation Instructor or Staff Navigation Officer.


Fourteen (14) weeks, with one course per year.


Maritime Warfare School, HMS Collingwood.

Entry Standards

  • Rank of Lieutenant with at least 5 years seagoing bridge experience since gaining the National equivalent of the RN’s Bridge Watchkeeping Certificate; of which at least 1 year must have been spent as the Navigating Officer of a Corvette or larger vessel.
  • A minimum of 2,000 hours certified Bridge Watchkeeping experience.
  • Eyesight standards as determined by the RN.

Outline of the Course

  • Passage planning.
  • Visual pilotage.
  • Blind pilotage and RADAR.
  • Ship handling.
  • Meteorology.
  • Relative velocity.
  • Navigation aids, GPS/Echo sounders/Logs/Gyros/Sextants (HSA/VSA and Lattice).
  • International Regulations for the Prevention of Collisions at Sea, aka Rule of the Road.
  • Practical instruction and assessment in a full mission Bridge Simulator conducting visual and blind pilotage by day and night.
  • Practical instruction and assessment in a Royal Navy warship (FF/DD/OPV) conducting visual and blind pilotage by day and night working closely with the ships Commanding Officer, Navigator, Officer of the Watch and Bridge Team.
  • Warship Electronic Chart Display & Information System (WECDIS).
  • Tides and time.
  • Chartwork.
  • Bridge resource management.
  • Magnetism and compass theory.
  • Naval gunfire support.
  • Astro-navigation.
  • International Maritime Law.
  • CASEX and submarine safety.
  • Helicopter operations.
  • Communications and Fleetwork (theory and practical naval manoeuvring).

Examinations/Qualifications Gained

Continuous assessment and final examinations to RN standards with pass marks requirement as follows:

  • Rule of the Road: 90%.
  • Chartwork and Fixing: 70%.
  • Tidal Theory, Tides, and Time: 70%.
  • General Navigation and Ship Handling, Two (2) Parts: 70%.
  • Astro-Navigation: 70%.
  • Sea Phase: 80%.

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