Maritime Officer & Cadet Examination: COLREG, Navigation, Safety, and Ship Operations

Comprehensive practice flashcards covering COLREG rules, lights, day shapes, sound signals, SOLAS, ISM Code, MARPOL annexes, navigation principles, electronic bridge equipment, ship stability, fire protection, and ICS flag recognition.

How many rules and annexes make up the COLREG 1972 convention, and what are its main parts?

COLREG consists of $38$ Rules divided into five parts: Part A General (Rules 1–3), Part B Steering and Sailing (Rules 4–19), Part C Lights and Shapes (Rules 20–31), Part D Sound and Light Signals (Rules 32–37), and Part E Exemptions (Rule 38), along with four Annexes (I Lights and shapes details, II Fishing vessels close together, III Sound appliances, IV Distress signals).

Under COLREG Rule 2, when is a vessel permitted to depart from the Rules?

A departure from the Rules is permitted when necessary to avoid immediate danger, with due regard paid to all dangers of navigation and collision and to any special circumstances.

How does COLREG Rule 3 define a vessel 'Restricted in her ability to manoeuvre' (RAM)?

A vessel restricted in her ability to manoeuvre is one that, from the nature of her work (such as laying cables or buoys, dredging, surveying, replenishment at sea, launching aircraft, mine clearance, or a towing operation that severely restricts the tow), is restricted in her ability to manoeuvre as required by the Rules.

What is the definition of a vessel 'Constrained by her draught' (CBD) under COLREG Rule 3?

A power-driven vessel severely restricted in her ability to deviate from the course she is following because of her draught in relation to the available depth and width of navigable water.

Under COLREG Rule 7, under what primary compass condition does a risk of collision exist?

Risk of collision exists if the compass bearing of an approaching vessel does not appreciably change. It can also sometimes exist even when an appreciable bearing change is evident, particularly when approaching a very large vessel or a tow, or at close range.

What are the sound signals used for overtaking in a narrow channel under COLREG Rule 9?

A vessel intending to overtake signals $2$ prolonged blasts followed by $1$ short blast (to overtake on the starboard side) or $2$ prolonged blasts followed by $2$ short blasts (to overtake on the port side). The overtaken vessel signals agreement by sounding prolonged – short – prolonged – short.

Under COLREG Rule 12, which vessel must give way when two sailing vessels are approaching each other?

When the wind is on different sides, the vessel with the wind on the port side gives way. When the wind is on the same side, the windward vessel gives way to the leeward vessel. If a vessel with the wind on the port side sees another to windward and cannot determine which side the other vessel has the wind on, she must give way.

How does COLREG Rule 13 define when a vessel is deemed to be overtaking another?

A vessel is overtaking when coming up with another vessel from a direction more than $22.5^\theta$ abaft her beam, such that at night she would be able to see only the sternlight of that vessel and neither of her sidelights.

What is the order of priority among vessels under COLREG Rule 18?

Each vessel must keep out of the way of those listed before it: Not under command (NUC) → Restricted in her ability to manoeuvre (RAM) → Fishing → Sailing → Power-driven. Additionally, all vessels except NUC and RAM avoid impeding a vessel constrained by her draught (CBD).

Under COLREG Rule 19, what specific course alterations should be avoided when detecting another vessel by radar alone in restricted visibility?

Avoid an alteration of course to port for a vessel forward of the beam (other than for a vessel being overtaken), and avoid an alteration of course towards a vessel abeam or abaft the beam.

What are the standard arcs of visibility for navigation lights under COLREG Rules 20–23?

Masthead light: $225^\theta$ (from dead ahead to $22.5^\theta$ abaft the beam on each side). Sidelights: $112.5^\theta$ each (green on starboard, red on port). Sternlight: $135^\theta$. Towing light: $135^\theta$ (yellow, above the sternlight). All-round light: $360^\theta$.

What day shape and night lights are required for a vessel constrained by her draught (CBD)?

At night, standard power-driven vessel lights plus three all-round red lights in a vertical line. By day, a black cylinder.

What lights and day shape are displayed by a vessel engaged in trawling?

At night, two all-round lights in a vertical line, green over white (plus sidelights and sternlight when making way). By day, two cones with their points together in a vertical line.

What day shapes are required for a vessel dredging or conducting underwater operations with an obstruction?

Two balls in a vertical line on the side on which the obstruction exists, and two diamonds in a vertical line on the side on which it is safe to pass.

What are the required visibility ranges of a masthead light under COLREG Rule 22 for vessels of different lengths?

Vessels of $50\text{ m}$ or more in length: $6\text{ nm}$. Vessels of $12\text{ m}$ to under $50\text{ m}$: $5\text{ nm}$ ($3\text{ nm}$ if under $20\text{ m}$). Vessels under $12\text{ m}$: $2\text{ nm}$.

What sound signals are prescribed under COLREG Rule 35 for vessels in restricted visibility?

Power-driven making way: $1$ prolonged blast every $2\text{ minutes}$. Power-driven underway but stopped and making no way: $2$ prolonged blasts every $2\text{ minutes}$ (about $2\text{ seconds}$ apart). NUC, RAM, CBD, sailing, fishing, towing or pushing: $1$ prolonged + $2$ short blasts every $2\text{ minutes}$. Manned vessel being towed (last in tow): $1$ prolonged + $3$ short blasts every $2\text{ minutes}$.

What are the four pillars of international maritime regulatory conventions?

SOLAS (Safety of Life at Sea), MARPOL (Prevention of Pollution from Ships), STCW (Standards of Training, Certification and Watchkeeping for Seafarers), and MLC 2006 (Maritime Labour Convention).

What are the minimum mandatory rest hours for seafarers established by MLC 2006?

At least $10\text{ hours}$ of rest in any $24\text{-hour}$ period, and at least $77\text{ hours}$ of rest in any $7\text{-day}$ period.

Under the ISM Code, what are the two primary certificates issued to confirm compliance, and to whom is each issued?

The Document of Compliance (DOC) is issued to the operating Company ashore by the flag administration, and the Safety Management Certificate (SMC) is issued to each individual ship.

What is the function and role of the Designated Person Ashore (DPA) under ISM Code Section 4?

The DPA provides a direct link between the ship and shore-based highest management, monitors the safety and pollution prevention aspects of each vessel, and ensures adequate resources and shore-based support are available.

What are the safety requirements and atmospheric limits for entering an enclosed space?

Perform a risk assessment and obtain a permit to work; ventilate the space; test the atmosphere (oxygen must be $20.9\%$, with no flammable or toxic gases); position a standby person outside in constant communication; have rescue and breathing apparatus ready. Nobody enters alone, and rescuers must not enter without raising the alarm and getting assistance.

What are the required conditions under MARPOL Annex I for discharging oily bilge water from machinery spaces?

The ship must be en route, the oil content of the effluent without dilution must not exceed $15\text{ ppm}$, and an operational oily water separator with an alarm and automatic stopping device must be in use.

Under MARPOL Annex V, what are the discharge distance limits for comminuted vs. uncomminuted food waste outside special areas?

Comminuted (ground) food waste capable of passing through a screen with openings no greater than $25\text{ mm}$ may be discharged at least $3\text{ nm}$ from the nearest land. Uncomminuted food waste must be discharged at least $12\text{ nm}$ from the nearest land.

What are the global and Emission Control Area (ECA) fuel sulphur limits established under MARPOL Annex VI?

The global sulphur limit is $0.50\%$ m/m, and the limit in Emission Control Areas (ECAs) is $0.10\%$ m/m (unless an approved alternative abatement technology, such as an exhaust gas scrubber, is fitted).

What are the four fundamental methods used to determine a ship's position at sea?

1. Dead reckoning: calculated from direction and rate of progress through the water starting from the latest well-determined position. 2. Piloting: directing vessel movements near shore by reference to landmarks, aids to navigation, or soundings. 3. Electronic navigation: positioning using electronic systems and devices. 4. Celestial navigation: position determined by observing celestial bodies (sun, moon, planets, stars).

What are the defining characteristics of an Orthodrome (great circle) versus a Loxodrome (rhumb line)?

An orthodrome represents the shortest distance between two points on a sphere, but has a continually changing compass course (variable course). A loxodrome represents a path of constant compass course, plots as a straight line on a Mercator projection chart, but covers a longer distance on extended voyages.

What is the formula for calculating the optical/radar horizon distance of a target?

$D = 2.2 \times (\sqrt{h_1} + \sqrt{h_2})$, where $D$ is the radar horizon distance in nautical miles, $h_1$ is the height of the radar antenna above sea level in metres, and $h_2$ is the height of the target above sea level in metres.

What are the wavelength, frequency, and operating advantages of X-band versus S-band radar?

X-band radar has a wavelength of $3\text{ cm}$ and frequency of $9\text{ GHz}$; it is more sensitive, uses a smaller antenna, and can detect SART signals. S-band radar has a wavelength of $10\text{ cm}$ and frequency of $3\text{ GHz}$; it is less affected by rain clutter, sea clutter, and fog, and detects large targets at longer ranges.

What are the carriage requirements for marine radar and ARPA based on ship gross tonnage?

$300\text{ GT}$ and above: an X-band radar. $3,000\text{ GT}$ and above: both X-band and S-band radars. $10,000\text{ GT}$ and above: both X-band and S-band radars, plus an ARPA (Automatic Radar Plotting Aid).

How is the Safety Contour calculated on ECDIS?

$\text{Safety Contour} = \text{Ship's Draught} + \text{Squat} + \text{Under-Keel Clearance (UKC)} - \text{Height of Tide}$.

What are the four consecutive stages of passage planning?

1. Appraisal: gathering all navigational, meteorological, and ship-specific information and evaluating risks. 2. Planning: laying out track lines, safety contours, no-go areas, abort points, and waypoints on charts. 3. Execution: briefing the bridge team and executing the route according to prevailing conditions. 4. Monitoring: continuous verification of the ship's position using independent primary and secondary methods.

What are the key execution steps for the three main Man Overboard manoeuvres shown?

Single turn (Anderson / $270^\circ$): Rudder hard over to the casualty side; after $250^\circ$ deviation, rudder midships and initiate stopping. Williamson turn: Rudder hard over to the casualty side; at $60^\circ$ deviation, rudder hard over to the opposite side; when $20^\circ$ short of reciprocal, rudder midships to roll onto opposite course. Scharnov turn: Rudder hard over; at $240^\circ$ deviation, rudder hard over to opposite side; when $20^\circ$ short of reciprocal, rudder midships to steady on opposite course.

What are the operational boundaries and defining infrastructure of GMDSS Sea Areas A1, A2, A3, and A4?

Sea Area A1: within radiotelephone coverage of at least one VHF coast station with continuous DSC alerting ($\text{Ch } 70$, approx. $20\text{–}30\text{ nm}$). Sea Area A2: within coverage of at least one MF coast station with continuous DSC ($2187.5\text{ kHz}$, approx. $100\text{–}150\text{ nm}$), excluding A1. Sea Area A3: within coverage of an INMARSAT geostationary satellite (approx. $70^\circ\text{N}$ to $70^\circ\text{S}$), excluding A1 and A2. Sea Area A4: the remaining polar areas outside A1, A2, and A3.

How does a Search and Rescue Radar Transponder (SART) operate and appear on a searching ship's display?

A SART responds when interrogated by a $9\text{ GHz}$ (X-band) radar. It transmits response signals displayed on the radar screen as a line of $12$ distinct dots extending outward along its bearing line. Typical detection ranges are approximately $5\text{ nm}$ by shipborne radar and $40\text{ nm}$ by aircraft.

What are the cargo groups categorized under the IMSBC Code?

Group A: cargoes that may liquefy if shipped at a moisture content above their Transportable Moisture Limit (TML) (e.g., nickel ore, iron ore fines). Group B: cargoes possessing chemical hazards (e.g., coal). Group C: cargoes that do not liquefy and possess neither chemical nor liquefaction hazards (e.g., cement, limestone).

In ship stability, what does Metacentric Height (GM) represent, and how do the relative positions of G and M determine equilibrium?

Metacentric height ($\text{GM}$) is the vertical distance between the centre of gravity ($\text{G}$) and the metacentre ($\text{M}$). If $\text{M}$ is above $\text{G}$, the ship has positive GM and is in stable equilibrium. If $\text{M}$ is below $\text{G}$, GM is negative and the ship is unstable. If $\text{M}$ coincides with $\text{G}$, GM is zero and equilibrium is neutral.

What is the difference between Gross Tonnage (GT) and Net Tonnage (NT)?

Gross Tonnage is a dimensionless index reflecting the overall internal enclosed volume of the vessel used for safety rules and official fees. Net Tonnage is an index of the volume of the cargo-earning spaces, representing the ship's commercial earning capacity used for harbour and canal dues.

What are the classes of fire defined under ISO 3941 and NFPA 10?

Under ISO 3941: Class A (carbonaceous solids), Class B (flammable liquids or liquefiable solids), Class C (flammable gases), Class D (combustible metals), Class F (cooking oils/fats). Under NFPA 10: Class A (ordinary combustibles), Class B (flammable liquids/gases), Class C (energized electrical equipment), Class D (combustible metals), Class K (cooking appliances using oils/fats).

Under SOLAS Chapter II-2, Regulation 10, how many spare charges must be carried for portable fire extinguishers?

For extinguishers rechargeable on board: spare charges for $100\%$ of the first $10$ extinguishers and $50\%$ of the remaining extinguishers, up to a maximum of $60$ spare charges. For extinguishers that cannot be recharged on board, complete identical spare extinguishers must be carried instead.

In the International Code of Signals (ICS), what is the letter and single-flag meaning of this flag?

Letter A (Alfa). Meaning: 'I have a diver down; keep well clear at slow speed.'

In the International Code of Signals (ICS), what is the letter and single-flag meaning of this flag?

Letter B (Bravo). Meaning: 'I am taking in or discharging or carrying dangerous goods.'

In the International Code of Signals (ICS), what is the letter and single-flag meaning of this flag?

Letter H (Hotel). Meaning: 'I have a pilot on board.'

In the International Code of Signals (ICS), what is the letter and single-flag meaning of this flag?

Letter G (Golf). Meaning: 'I require a pilot.' (By fishing vessels near fishing grounds: 'I am hauling nets.')

In the International Code of Signals (ICS), what is the letter and single-flag meaning of this flag?

Letter O (Oscar). Meaning: 'Man overboard.'

In the International Code of Signals (ICS), what is the letter and single-flag meaning of this flag?

Letter Q (Quebec). Meaning: 'My vessel is "healthy" and I request free pratique.'

In the International Code of Signals (ICS), what is the letter and single-flag meaning of this flag?

Letter U (Uniform). Meaning: 'You are running into danger.'

In the International Code of Signals (ICS), what is the letter and single-flag meaning of this flag?

Letter V (Victor). Meaning: 'I require assistance.'

In the International Code of Signals (ICS), what is the letter and single-flag meaning of this flag?

Letter W (Whiskey). Meaning: 'I require medical assistance.'

In the International Code of Signals (ICS), what is the letter and meaning of this flag in harbour versus at sea?

Letter P (Papa / The Blue Peter). In harbour: 'All persons should report on board as the vessel is about to proceed to sea.' At sea (by fishing vessels): 'My nets have come fast upon an obstruction.'