Guidance

Officer of the Watch Unlimited MCA digital assessment syllabus (operational) – Navigation, stability and operations

Published 20 March 2026

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This publication is available at https://www.gov.uk/government/publications/mca-deck-digital-assessment-syllabuses/officer-of-the-watch-unlimited-mca-digital-assessment-syllabus-operational-navigation-stability-and-operations

1. Following a passage plan

  1. This includes the ability to:

    1. a) Discuss the procedures for executing and monitoring the progress on a passage plan of a vessel on a pre-planned track.
    2. b) Apply passage planning principles to navigate through specialised areas, such as, Traffic Separation Schemes and Offshore Energy Installations.
    3. c) Identify charted objects suitable for position fixing.
    4. d) Identify chart symbols and abbreviations.
    5. e) Explain the factors to be considered when making landfall.

2. Routeing instructions and guidelines

  1. This includes the ability to:

    1. a) Interpret the International Regulations for the Prevention of Collisions at Sea (IRPCS) Rule 10.
    2. b) Explain use the of the International Maritime Organization (IMO) Ship’s Routeing Guide and other Routeing Guides.

3. Adjust vessel’s course and speed to take account of passage plan requirements

  1. This includes the ability to:

    1. a) Plot the position of the vessel on a chart using position lines derived from charted objects.
    2. b) Adjust vessel course and/or speed to comply with the passage plan.
    3. c) Determine standard and/or gyro compass errors to convert True to Compass and vice versa for the ship’s head and bearings.
    4. d) Determine adjustments to course for a change in standard or gyro compass error.

4. The Sailings (plane, parallel and mercator)

  1. This includes the ability to:

    1. a) Compute estimated time of arrival (ETA), accounting for a desired or expected speed and applicable time zones.

5. Finding the tidal information at standard ports – Worldwide

  1. This includes the ability to:

    1. a) Find the height and time of high and low water using tide tables.
    2. b) Compute the predicted height or time of tide at a given position using tide tables and tidal curves.
    3. c) Discuss the reliability of tidal predictions.
    4. d) Compute the correction of soundings to chart datum.

Stability and operations digital assessment syllabus

6. Maintaining a Deck Watch in port, at anchor and at sea

  1. This includes the ability to:

    1. a) Understand the responsibilities of the Officer of the Watch (OOW) under potential watchkeeping situations, including navigational, port, cargo, and anchor watches, ensuring compliance with relevant maritime regulations and operational procedures.

7. Hydrostatics – Flotation, buoyancy and load lines

  1. This includes the ability to:

    1. a) Apply Fresh Water Allowance (FWA), Dock Water Allowance (DWA) and Tonnes Per Centimetre (TPC).
    2. b) Use hydrostatic data to determine displacement and TPC for varying draughts and water densities.
    3. c) Compute the weight to load and discharge to obtain intended draught or freeboard using hydrostatic data.
    4. d) Compute weight to load or discharge in relation to load line dimensions, appropriate marks, TPC, FWA and DWA.

8. Transverse stability

  1. This includes the ability to:

    1. a) Compute the Moment of Statical Stability (MSS or righting moment) using displacement and the righting lever (GZ).
    2. b) Understand the principles governing stable, neutral and unstable equilibrium.
    3. c) Demonstrate the understanding of the phenomenon of angle of loll and vessel’s equilibrium in that condition.
    4. d) Interpret key parameters from a given statical stability curve, including the condition and range of stability, initial metacentric height (GM), maximum GZ, angle of maximum GZ, angle of vanishing stability, angle of deck edge immersion, and the angle of loll or list, if applicable.
    5. e) Interpret the factors governing curves of statical stability for stiff and tender vessels.
    6. f) Compute the final effective distance from the keel to the centre of gravity (KG) or GM, and the resulting angle of list following the loading, discharging, or shifting of weights, including operations involving the use of the ship’s cargo gear.
    7. g) Understand the difference between the angle of list and the angle of loll, and the appropriate corrective measures.
    8. h) Understand free surface effect, the virtual loss of GM and associated consequences and dangers.
    9. i) Understand the effects of liquid density and longitudinal subdivision of compartments on the magnitude of free surface effect.

9. Longitudinal stability

  1. This includes the ability to:

    1. a) Apply the key principles of longitudinal stability to problems related to loading/discharging/shifting weights on vessels to achieve an even keel or specified trim.

    2. Key principles of longitudinal stability:
    3. • True Mean Draft (TMD)
    4. • Longitudinal Centre of Flotation (LCF)
    5. • Longitudinal Centre of Gravity (LCG)
    6. • Longitudinal Centre of Buoyancy (LCB)
    7. • Aft Perpendicular (AP)
    8. • Forward Perpendicular (FP)
    9. • Length Between Perpendiculars (LBP)
    10. • Amidships
    11. • Trim
    12. • Trimming Moment
    13. • Moment to Change Trim by One Centimetre (MCTC)

For more information about the MCA digital assessment syllabus (operational) email -exams@mcga.gov.uk.

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