Navigation
What the navigation paper tests
The navigation paper checks that you can plan and monitor a coastal or short-sea passage without depending entirely on electronics: chartwork, position fixing, compass work, current and tidal calculations, and IALA Region A buoyage as used along the Norwegian coast.
Core rules and concepts
- Plot fixes at an interval set by speed and risk; a three-point fix is strongest when the objects subtend angles near 60 to 120 degrees.
- A running fix advances the earlier line of position along the course and distance steamed; its accuracy depends on your estimate of set and drift.
- Soundings and drying heights are referenced to chart datum (about LAT). Light heights are given above mean high water springs, so the range you actually see depends on height of eye and meteorological visibility.
- Compass to true: apply deviation (east positive) to get magnetic, then variation (east positive) to get true. True to compass reverses both steps.
- IALA Region A: red can buoys to port on entry, green cones to starboard. Cardinal marks use two cones and the clock face to show where the safe water lies.
Worked example
Required course over ground 090°T, speed through water 10 kn, current setting 180°T at 2 kn on the starboard beam. Cancel the cross-track component: sin(angle) = 2 / 10 = 0.20, so steer 11.5 degrees into the current, course 078.5°T. Speed made good = 10 x cos 11.5 = 9.80 kn. For 20 nm the run takes 20 / 9.80 = 2 h 02 min.
Traps that cost marks
- Sign errors when combining deviation and variation; check which way the compass actually reads.
- Confusing set (direction toward which the current flows) with the direction it comes from.
- Forgetting that a gyro error named high means the gyro reads more than true.
- Answering buoyage from Region B memory, where red is to starboard on entry.