BD Deck Officer Class 3 (OOW) flashcards

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

Great-circle distance formula

Cosine rule: cos D = sin φ1·sin φ2 + cos φ1·cos φ2·cos Δλ. Multiply the resulting angular distance in degrees by 60 to obtain nautical miles.

Set and drift

Set is the direction toward which a current flows; drift is its speed in knots. Both are applied as a vector opposite to the desired course to find the course to steer.

Radar horizon formula

Range in nautical miles equals 1.23 times the square root of antenna height in metres plus 1.23 times the square root of target height in metres.

Buys Ballot's law

In the Northern Hemisphere, with your back to the wind, low pressure lies to your left. In the Southern Hemisphere, low pressure lies to your right.

Beaufort 10 wind speed

Beaufort force 10 is a storm with wind speed 48 to 55 knots. Force 12 is a hurricane at 64 knots or above.

Dew point and fog

Fog forms when air cools to its dew point. Radiation fog forms overnight over land; advection fog forms when warm moist air crosses a cold sea surface.

Metacentric height formula

GM equals KM minus KG. Positive GM gives a righting moment; negative GM means initial instability and can lead to an angle of loll.

Free surface correction

Free surface effect reduces effective GM by an amount equal to the second moment of area of the free surface times density, divided by displacement.

Tons per centimetre immersion

TPC equals waterplane area in square metres times water density in tonnes per cubic metre, divided by 100.

Broken stowage

Broken stowage is the volume of a hold not occupied by cargo, expressed as a percentage of the hold's total volume.

IMDG segregation code 3

Code 3 means the goods must be separated by one complete compartment or hold from the other goods. Code 4 requires two compartments.

Stowage factor

Stowage factor is the volume in cubic metres occupied by one tonne of cargo. Low values indicate dense, heavy cargo; high values indicate light cargo.

STCW rest hours

A minimum of 10 hours rest in any 24-hour period and 77 hours in any seven-day period. Rest may be split into no more than two periods.

Enclosed space entry test

Before entry, test oxygen (minimum 20 percent), flammable gas, and toxic gas. Continue testing during the entry and maintain a standby person at the entrance.

Rule 15 crossing situation

When two power-driven vessels cross, the vessel with the other on her starboard side gives way. The stand-on vessel keeps course and speed.

Rule 19 restricted visibility

In restricted visibility, proceed at a safe speed and avoid altering course to port for a vessel forward of the beam, unless overtaking.

Risk of collision test

Risk of collision exists if the compass bearing of an approaching vessel does not appreciably change. Any doubt means risk exists.

Steering gear SOLAS test

The main and auxiliary steering gear must be able to put the rudder from 35 degrees on one side to 35 degrees on the other in 28 seconds at full speed.

Oily water separator limit

Discharge overboard is permitted only under 15 parts per million through an oil filtering and monitoring system, and not in special areas.

Two-stroke diesel cycle

Scavenge air enters through cylinder ports and exhaust leaves through a central valve. A power stroke occurs once every revolution of the crankshaft.

MARPOL Annex VI sulphur limit

The global sulphur limit is 0.50 percent. In emission control areas the limit is 0.10 percent, covering the Baltic, North Sea, North America, and US Caribbean.

Annex V garbage discharge

Garbage discharge is prohibited within 3 nautical miles of land. Comminuted food waste may be discharged beyond 3 nm, and outside special areas beyond 12 nm.

Ballast water D-1 standard

Ballast water exchange must occur at least 200 nautical miles from land in water at least 200 metres deep, or meet the D-2 treatment standard.

UNCLOS maritime zones

The territorial sea extends 12 nautical miles, the contiguous zone 24 nm, the exclusive economic zone 200 nm, and the continental shelf to its natural prolongation.

STCW certificate requirements

STCW sets minimum standards for certification, watchkeeping, and rest hours. Certificates of competency require sea service, training, and examination.

DSC distress alert frequencies

VHF Channel 70 or MF/HF 2187.5 kHz. Follow the alert with voice communication on VHF Channel 16 or MF 2182 kHz.

SART radar signature

A SART is a 9 GHz radar transponder that shows twelve dots on a ship's radar display. Its range is about 5 to 8 nautical miles.

EPIRB frequency

The 406 MHz EPIRB operates through the Cospas-Sarsat system. It must be float-free mounted and registered with the flag State.

Fire classes

Class A is solid, B liquid, C gas, D metal, E electrical, F cooking oil. Water is unsuitable for B, C, E, and F fires.

CPR compression ratio

Give 30 chest compressions followed by 2 ventilations at a rate of 100 to 120 compressions per minute and a depth of 5 to 6 centimetres.

Emergency generator start time

The emergency generator must start and supply emergency loads within 45 seconds of the main power failure.

Severe bleeding control

Apply direct pressure to the wound and elevate the limb. Use a tourniquet as a last resort and record the time it was applied.