KMA Cadet 1st-Stage Exam cheat sheet

Latitude is angular distance north or south of the equator, measured 0°–90°; longitude is angular distance east or west of the prime meridian, measured 0°–180°.

1 minute of latitude equals 1 nautical mile (1,852 m); 1 degree of latitude equals 60 nautical miles.

Speed, distance, time: Distance (nm) = Speed (kn) × Time (h); Time = Distance ÷ Speed; Speed = Distance ÷ Time.

True bearing = magnetic bearing + variation (east add, west subtract); compass bearing = magnetic bearing + deviation (east add, west subtract).

Great-circle course is the shortest path on a sphere; rhumb line maintains constant bearing and appears as a straight line on a Mercator chart.

Mercator projection: meridians are parallel straight lines, latitude scale increases toward the poles, and the rhumb line is a straight line.

A fix is a position determined from two or more position lines (e.g., bearings, ranges, GPS); a running fix advances a single position line using course and speed.

Rule of thumb: deviation east, compass least; deviation west, compass best (for converting compass to magnetic).

Under COLREGs, a vessel overtaking another must keep clear; the overtaken vessel must maintain course and speed.

Two-stroke slow-speed diesel engines directly drive fixed-pitch propellers at 70–120 rpm; four-stroke medium-speed engines drive through reduction gears.

Indicated power (Pi) = planimeter area × spring constant × engine rpm × number of cylinders × constant; brake power = indicated power − friction power.

Specific fuel oil consumption (SFOC) = fuel mass flow rate ÷ brake power, typically 160–190 g/kWh for large two-stroke engines.

Propeller law: power varies approximately with the cube of shaft speed (P ∝ N³); thrust varies with the square of shaft speed (T ∝ N²).

A controllable-pitch propeller allows engine speed to remain constant while blade pitch changes to vary thrust and direction.

Turbochargers use exhaust gas energy to drive a turbine that compresses scavenge air, increasing power density and efficiency.

Cavitation occurs when local pressure drops below vapour pressure, causing bubble collapse, noise, erosion, and loss of thrust.

Freshwater cooling systems use a heat exchanger with seawater; jacket water temperature is typically maintained at 70–85 °C.

Principal dimensions: Length overall (LOA), length between perpendiculars (LBP), moulded breadth (B), moulded depth (D), and design draught (T).

Block coefficient (Cb) = volume of displacement ÷ (LBP × B × T); typical values: tankers 0.80–0.85, container ships 0.60–0.70.

Longitudinal strength is provided by the keel, centre girder, side girders, longitudinal stiffeners, and deck plating; transverse strength by frames and floors.

Freeboard is the vertical distance from the summer load line to the freeboard deck; minimum freeboard is governed by the International Convention on Load Lines.

Load line marks: S = summer, W = winter, T = tropical, F = fresh water, TF = tropical fresh water, and WNA = winter North Atlantic.

Double-bottom and double-hull construction reduce pollution risk in grounding and collision; required for oil tankers under MARPOL Annex I.

Watertight subdivision limits flooding; the collision bulkhead is located at least 0.05L or 10 m (whichever is less) from the forward perpendicular.

Corrosion protection includes sacrificial anodes (cathodic protection) and protective coatings; steel wastage limits are set by classification societies.

Archimedes' principle: buoyancy force equals the weight of displaced fluid; for a floating body, displacement = weight.

GM (metacentric height) = KM − KG; positive GM indicates initial stability, negative GM indicates unstable equilibrium.

Righting moment = displacement × GZ; GZ = GM × sin θ for small angles of heel (up to about 10°).

Free surface effect reduces effective GM: FSC = (moment of inertia of free surface × density of liquid) ÷ (displacement × density of water).

Angle of loll is the angle at which a vessel with negative GM may rest; it can be corrected by lowering G (adding ballast to double bottom) or reducing free surface.

Load line marks ensure minimum freeboard; overloading reduces reserve buoyancy and stability.

Life-saving appliances: SOLAS requires lifeboats, liferafts, lifebuoys, and immersion suits according to vessel type and complement.

Fire triangle: fuel, oxygen, heat; fire classes A (solids), B (flammable liquids), C (gases), D (metals), and electrical fires.

Enclosed space entry requires atmosphere testing (oxygen 20.9%, hydrocarbons <1% LFL, toxic gases below limits) and a permit-to-work.

UNCLOS establishes territorial sea (12 nm), contiguous zone (24 nm), exclusive economic zone (200 nm), and high seas.

Innocent passage through the territorial sea must be continuous and expeditious and not prejudicial to the peace, good order, or security of the coastal state.

Flag state exercises jurisdiction over ships on the high seas; port state control inspects foreign ships in port for compliance with conventions.

A bill of lading is a receipt for goods, evidence of the contract of carriage, and a document of title; it may be negotiable.

Hague-Visby Rules, Hamburg Rules, and Rotterdam Rules govern carrier liability for cargo; they set limits per package or per kilogram.

General average: sacrifice or expenditure intentionally and reasonably made for the common safety is shared proportionally by cargo, ship, and freight.

Salvage under the 1989 Salvage Convention is rewarded based on saved value, with special compensation for preventing environmental damage.

Collision liability is apportioned by degree of fault; the 1910 Collision Convention and COLREGs determine fault.

SOLAS (International Convention for the Safety of Life at Sea) covers construction, fire protection, life-saving appliances, radio communications, and navigation safety.

MARPOL has six technical annexes: I oil, II noxious liquid substances, III harmful substances in packaged form, IV sewage, V garbage, VI air pollution.

MARPOL Annex VI sets sulphur limits (0.50% global from 2020, 0.10% in ECAs) and NOx Tier limits for new engines.

STCW sets minimum standards for training, certification, and watchkeeping; certificates require sea service and approved training.

MLC 2006 consolidates maritime labour standards: minimum age, hours of work, accommodation, health protection, and complaint procedures.

ISM Code requires a Safety Management System (SMS) with documented procedures, designated person ashore, and internal audits.

ISPS Code establishes security levels 1–3 and requires a Ship Security Plan and Ship Security Officer.

BWM Convention regulates ballast water management to prevent transfer of invasive aquatic species; D-1 exchange or D-2 treatment standard.

IMO conventions enter into force after a specified number of states and percentage of world tonnage ratify them.

Freight market equilibrium: freight rate is determined by supply (fleet capacity) and demand (seaborne trade); inelastic short-run supply causes rate volatility.

Laytime is the period allowed for loading/discharging; demurrage is compensation for exceeding laytime; despatch is a reward for finishing early.

Voyage charter: owner pays operating costs and voyage costs; time charter: charterer pays voyage costs (bunkers, port charges) and hire is paid per day.

Bareboat charter: charterer pays all operating and voyage costs and assumes technical management.

Worldscale is a nominal freight rate index for tankers; the actual rate is a percentage of the Worldscale flat rate.

Baltic Dry Index (BDI) is a composite of Capesize, Panamax, and Supramax/Handysize indices, reflecting dry bulk freight rates.

Ship operating costs include crew, stores, lubricants, maintenance, insurance, and administration; capital costs include financing and depreciation.

Economies of scale: larger vessels have lower cost per tonne-mile but require deeper ports and larger cargo volumes.

Port turnaround time is the total time a ship spends in port, from arrival to departure, including waiting, berthing, cargo operations, and formalities.

Berth productivity is measured in moves per hour (container terminals) or tonnes per day (bulk terminals).

Just-in-time (JIT) arrival reduces anchorage waiting and emissions by coordinating vessel arrival with berth availability.

Terminal operating systems (TOS) manage container yard, gate, and vessel operations; EDI messages include BAPLIE and MOVINS.

Bill of lading types: straight (non-negotiable), order (negotiable), and bearer; a clean B/L indicates goods received in apparent good order.

Incoterms (e.g., FOB, CIF, CFR) define cost, risk, and responsibility transfer between seller and buyer in international trade.

Hinterland connectivity (rail, road, barge) determines port competitiveness and container dwell time.

Port state control inspections target substandard ships using risk-based ship selection criteria.

MARPOL Annex I prohibits oily water discharge with oil content exceeding 15 ppm; the oil record book must record all transfers and discharges.

An oil-water separator (15 ppm alarm) and oily water holding tank are required equipment on board.

MARPOL Annex V bans discharge of plastics and garbage into the sea; food waste discharge is permitted only beyond specified distances from land.

MARPOL Annex IV regulates sewage discharge; comminuted and disinfected sewage can be discharged beyond 3 nm, untreated beyond 12 nm (with conditions).

MARPOL Annex VI sulphur emission control areas (ECAs) include the Baltic Sea, North Sea, North American, and US Caribbean Sea areas.

Ballast water exchange (D-1) requires at least 200 nm from land and 200 m depth, or 50 nm if not possible, with 95% volumetric exchange.

Anti-fouling systems: the AFS Convention bans organotin compounds; ships must carry an International Anti-Fouling System Certificate.

Ship recycling is governed by the Hong Kong Convention (not yet in force) and the EU Ship Recycling Regulation.

Oil spill response uses booms, skimmers, and dispersants; the polluter-pays principle and CLC/Fund Convention provide compensation.

SMCP (Standard Marine Communication Phrases) are used for safety communications; they are not a substitute for plain language when necessary.

Mayday: distress call (grave and imminent danger); Pan-Pan: urgency call; Sécurité: safety call.

In VHF radiotelephony, use channel 16 for distress, urgency, and calling; channel 13 for bridge-to-bridge navigation.

Message structure: station called, station calling, message; use phonetic alphabet (Alfa, Bravo, Charlie...) and numerals (one, two, three...).

In a distress message, include: MAYDAY, vessel name, call sign, position, nature of distress, assistance required, number of persons on board.

Bridge team communication: closed-loop communication requires the receiver to repeat back orders and the giver to confirm.

Standard helm orders: 'Port ten', 'Starboard ten', 'Midships', 'Meet her', 'Steady as she goes'.

In English, 'mooring' refers to securing a vessel; 'anchoring' is dropping anchor; 'berthing' is coming alongside.

IMO is the UN specialized agency for shipping safety and pollution prevention; it has 175+ member states and is headquartered in London.

Major ship registries: Panama, Liberia, Marshall Islands, Hong Kong, Singapore; flag of convenience denotes open registries.

Container ship sizes: Feeder (<3,000 TEU), Panamax (4,000–5,000 TEU), Post-Panamax (5,000–10,000 TEU), ULCV (>20,000 TEU).

Bulk carrier sizes: Handysize (10,000–35,000 dwt), Handymax/Supramax (35,000–60,000 dwt), Panamax (60,000–80,000 dwt), Capesize (100,000+ dwt).

Tanker sizes: MR (Medium Range, 30,000–50,000 dwt), LR1 (55,000–80,000 dwt), LR2 (80,000–160,000 dwt), VLCC (200,000+ dwt).

IMO 2020 sulphur cap reduced marine fuel sulphur from 3.50% to 0.50% globally; scrubbers or compliant fuels are used.

IMO GHG strategy targets net-zero emissions from international shipping by or around 2050, with indicative checkpoints for 2030 and 2040.

The Suez Canal and Panama Canal are major chokepoints; canal transits depend on vessel dimensions and draught limits.

Arctic shipping is increasing due to ice retreat; the Polar Code regulates ship design, equipment, and operations in polar waters.

Pythagorean theorem: a² + b² = c² for right triangles; used for distance and vector problems.

Trigonometry: sin θ = opposite/hypotenuse; cos θ = adjacent/hypotenuse; tan θ = opposite/adjacent.

Law of sines: a/sin A = b/sin B = c/sin C; law of cosines: c² = a² + b² − 2ab cos C.

Area of a triangle = ½ × base × height; area of a circle = πr²; circumference = 2πr.

Volume of a rectangular tank = length × breadth × depth; volume of a cylinder = πr²h.

Percentage change = (new value − old value) ÷ old value × 100%.

Simple interest: I = P × r × t; compound interest: A = P(1 + r/n)^(nt).

Mean = sum of values ÷ number of values; median is the middle value when ordered; mode is the most frequent value.

Unit conversion: 1 nautical mile = 1,852 m; 1 knot = 1 nm/h; 1 tonne = 1,000 kg; 1 bar = 100 kPa.

Newton's second law: F = ma; weight = mg, with g ≈ 9.81 m/s².

Pressure = force ÷ area; hydrostatic pressure = ρgh, where ρ is fluid density, g is gravity, h is depth.

Density = mass ÷ volume; relative density (specific gravity) = density of substance ÷ density of fresh water.

Work = force × distance; power = work ÷ time; 1 kW = 1,000 W; 1 hp = 0.7457 kW.

Thermal expansion: ΔL = α L ΔT; α is the coefficient of linear expansion.

Heat transfer: conduction (through solids), convection (fluids), radiation (electromagnetic waves).

Electrical Ohm's law: V = IR; power P = VI = I²R = V²/R.

Stress = force ÷ area; strain = change in length ÷ original length; Hooke's law: stress ∝ strain within elastic limit.

Bernoulli's principle: increase in fluid speed occurs simultaneously with decrease in pressure or potential energy.