Chief Mate CoC flashcards

37 cards. Read the term and the definition here. The deck at the top of this page is optional.

Great circle distance formula

D = 60 × arccos(sin φ1 sin φ2 + cos φ1 cos φ2 cos Δλ), where φ1 and φ2 are latitudes in degrees and Δλ is the smaller longitude difference. Result in nautical miles.

Mercator sailing formula

DMP = 7915.7 × log10[tan(45° + φ/2)] minutes. Course angle C = atan(Δλ / DMP); distance = Δφ / cos C. Used for rhumb line courses.

Squat formula

Squat (m) ≈ Cb × V² / 100 in open water, doubled in confined channels. Cb = block coefficient, V = speed in knots. Reduces under-keel clearance.

IALA Region A buoyage

Red can buoys mark port hand and green conical buoys mark starboard hand when entering from sea. Region B reverses these colours (red to starboard).

GM and stability condition

GM = KM − KG. Positive GM means stable equilibrium; negative GM means unstable and will capsize; GM = 0 means neutral equilibrium. Free surface effect reduces GM.

Angle of loll formula

cos θ = √(2 GM / BM) for negative GM. Ship lists unpredictably to port or starboard. Correct by lowering KG (ballast in double bottoms) before righting.

Free surface correction

FSC = (i × ρ_liquid) / (Δ × ρ_water), where i is the second moment of the free surface area about its centreline. Reduces effective GM.

Cargo liquefaction TML

TML (transportable moisture limit) = 90% of flow moisture point. Bulk cargo with moisture above TML must not be loaded (IMSBC Code).

Buys Ballot's Law

In Northern Hemisphere, with back to wind, low pressure is to your left. In Southern Hemisphere, low pressure is to your right. Used to locate storm centres.

TRS avoidance dangerous semicircle

In Northern Hemisphere, dangerous semicircle is right of storm track. Steer to bring wind on starboard bow and move away from centre. In navigable semicircle, keep wind on starboard quarter.

Beaufort force 8

Gale: wind speed 34–40 knots. Force 6 = 22–27 kn (strong breeze); force 10 = 48–55 kn (storm); force 12 = ≥64 kn (hurricane).

Advection fog formation

Forms when warm moist air moves over a cold surface (sea fog). Radiation fog requires clear sky, light wind, and high relative humidity. Both reduce visibility.

Collision bulkhead location

Located at not less than 0.05L and not more than 0.08L (or 0.05L + 3 m, whichever is greater) from the forward perpendicular (SOLAS II-1).

Double bottom height

Not less than B/20 or 760 mm, whichever is greater (SOLAS II-1/9). Minimum 600 mm at the keel. Provides grounding protection and ballast capacity.

Hogging and sagging

Hogging: wave amidships, buoyancy ends - deck tension, keel compression. Sagging: wave at ends - reverses. Avoid excessive ballast transfer in heavy weather.

Load line marks order

S = summer, W = winter, T = tropical, F = fresh water, TF = tropical fresh, WNA = winter North Atlantic. Freeboard decreases from W to T to S.

UNCLOS maritime zones

Territorial sea 12 nm from baseline; contiguous zone 24 nm; exclusive economic zone 200 nm; high seas beyond. Innocent passage applies in territorial sea.

Hague-Visby Rules time bar

One-year time bar for suit. Carrier must exercise due diligence to make ship seaworthy before and at beginning of voyage. Applies to bills of lading.

General average

Sacrifice or expenditure intentionally and reasonably made for common safety. Contribution by all cargo interests in proportion to arrived values (York-Antwerp Rules).

LLMC limitation amounts

LLMC 1976/1996 Protocol: 2 million SDR for loss of life, 1 million SDR for property (for ships ≤ 2,000 GT). Increases with tonnage.

MARPOL Annex VI sulphur cap

Global sulphur cap 0.50% m/m from 1 Jan 2020. 0.10% in ECAs: Baltic, North Sea, North American, US Caribbean, Mediterranean from 1 May 2025.

STCW rest hours

Minimum 10 hours rest in any 24-hour period and 77 hours in any 7-day period. Maximum 14 hours on duty in any 24-hour period. Rest in max two periods, one ≥6 hours.

ISM Code DPA

Company must designate a person ashore (DPA) with direct access to highest management. SMS functional requirements; internal audits annually; external audit by flag State.

ISPS security levels

Three levels: Level 1 normal, Level 2 heightened, Level 3 exceptional. Ship security plan (SSP), SSO, CSO, PFSO. Applies to ships and port facilities.

COLREG Rule 14 head-on

Both vessels alter course to starboard and pass port-to-port. Applies when two power-driven vessels meet on reciprocal or nearly reciprocal courses with risk of collision.

COLREG Rule 15 crossing

Vessel with other on her starboard side gives way. Avoid crossing ahead. The give-way vessel should take early and substantial action.

COLREG Rule 19 restricted visibility

Reduce speed to minimum steerage way. No right of way. Avoid altering course to port for vessel forward of beam. Sound fog signals per Rule 35.

Muster list and drills

Muster list posted before sailing. Abandon ship and fire drills monthly for crew; passenger ships weekly. Drills within 24 hours of leaving port if >25% crew new.

Emergency generator start time

Must start automatically and supply emergency switchboard within 45 seconds (SOLAS II-1/43). Provides power for emergency lighting, steering, and radio.

Material condition Zebra

All watertight closures secured. Set for action stations or general emergency. X-ray = least restrictive; Yoke = intermediate; Zebra = maximum watertight integrity.

Two-stroke diesel scavenging

Uniflow scavenging with exhaust valve and crosshead. Typical BMEP 18–20 bar; specific fuel consumption ~165–175 g/kWh. Used for slow-speed propulsion.

Steering gear SOLAS requirement

Two independent power units required (SOLAS II-1/29). Test before departure. Emergency steering drill every 3 months. Main and auxiliary steering gear.

Just culture

Distinguishes human error (console), at-risk behaviour (coach), reckless behaviour (sanction). Encourages reporting without fear. Part of safety management.

Safety culture levels

Reason's model: pathological, reactive, calculative, proactive, generative. Generative is highest - safety is a core value, not just a priority.

Oil record book retention

MARPOL Annex I: Part I (machinery space) and Part II (cargo). Entries for ballasting, cleaning, discharge. Retained 3 years on board.

MARPOL Annex V garbage discharge

No discharge of plastics anywhere. Food waste ≥12 nm (comminuted ≥3 nm). Cargo residues ≥12 nm. Garbage record book retained 2 years.

Ballast water management D-2

BWM Convention 2004: D-1 exchange (sequential or flow-through, 95% volumetric) or D-2 treatment. BWRB retained 2 years. IOPP certificate required.