SAMSA Skipper Category C (Coastal, up to 15 nm) Exam (South Africa) flashcards
SAMSA Skipper Category C (Coastal, up to 15 nm) Exam (South Africa) · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Nautical mile
- One minute of latitude, equal to 1 852 metres, used as the standard unit of distance at sea.
- Dead reckoning
- A position calculated from the last known fix advanced by course steered and speed through the water, corrected for current and leeway.
- Variation
- The angle between true north and magnetic north at a location, caused by the Earth's magnetic field and shown on the chart's compass rose.
- Deviation
- The error in a magnetic compass caused by the vessel's own magnetic fields, specific to the vessel and its heading.
- Mercator chart scale
- On a Mercator chart the scale increases with latitude, so distance must be measured on the latitude scale at the vessel's own latitude.
- Spring tides
- Tides of greatest range occurring near new and full moon, when the Sun and Moon's tidal forces are aligned.
- Neap tides
- Tides of smallest range occurring near the quarter moons, when the Sun and Moon's tidal forces partly oppose each other.
- Rule of twelfths
- A method estimating tidal height change over six hours, dividing the range into twelfths: 1,2,3,3,2,1 per hour.
- Chart datum
- The reference level from which charted depths are measured, normally close to Lowest Astronomical Tide so depths are minimum expected.
- Set and drift
- Set is the direction toward which a current flows; drift is the speed of that current in knots.
- Buys Ballot's law
- In the southern hemisphere, standing with your back to the wind places low pressure to your left and high pressure to your right.
- Sea breeze
- A local wind blowing from sea to land by day, caused by land heating faster than the adjacent sea surface.
- Advection fog
- Fog formed when warm moist air moves over a colder sea surface and is cooled below its dew point.
- Agulhas Current
- A strong south-west flowing current along the east coast of South Africa that can produce steep short seas against a north-east wind.
- Cold front passage
- The passage of a cold front brings a wind shift, often to the south-west in South African waters, with squalls and rain.
- Give-way vessel
- In a crossing situation, the vessel with the other on her starboard side must keep clear of the stand-on vessel.
- Three short blasts
- A sound signal meaning the vessel is operating astern propulsion, used when manoeuvring astern.
- Not under command lights
- Two all-round red lights in a vertical line at night, and two black balls by day, shown by a vessel unable to manoeuvre.
- Sidelights
- A red light on the port side and a green light on the starboard side, each showing from ahead to 22.5 degrees abaft the beam.
- IALA Region A
- The buoyage system used in South Africa: red can buoys mark the port side of a channel when entering from seaward.
- Cardinal marks
- Buoys with cone topmarks indicating the safe side to pass: north two cones up, east base-to-base, south two cones down, west point-to-point.
- Safe water mark
- A buoy with red and white vertical stripes and a single red sphere topmark, marking navigable water all around.
- Isolated danger mark
- A black buoy with a red band and two black spheres, placed on a danger with safe water all around it.
- Light characteristic
- The colour, period and phase pattern of a light, for example Fl(2)R 10s meaning a red group of two flashes every 10 seconds.
- Bowline
- A knot forming a fixed loop that will not slip, used for securing a line around a post or to a person.
- Anchor scope
- The ratio of anchor chain or rope paid out to the depth of water, typically 5 to 7 times the depth.
- Spring line
- A mooring line led fore and aft to prevent a vessel moving ahead or astern alongside a berth.
- MAYDAY
- The distress signal for grave and imminent danger requiring immediate assistance, transmitted on VHF channel 16.
- PAN PAN
- The urgency signal used for urgent but non-immediate danger, sent on VHF channel 16.
- DSC distress alert
- A digital distress alert sent on VHF channel 70, followed by a voice MAYDAY call on channel 16.
- Category C skipper
- A SAMSA certificate of competency permitting coastal operation up to 15 nautical miles from the South African coast.
- Free surface effect
- The loss of stability caused by liquid moving freely in a partly filled tank, raising the effective centre of gravity.