NAV_EXAM Flashcards
Enumeration
4 types of bearing
- true bearing
- relative bearing
- magnetic bearing
- compass bearing
Enumeration
4 cardinal point of a compass
SOUTH
NORTH
EAST
WEST
Enumeration
3 types of north
True north
Magnetic north
Grid North
Enumeration
4 Errors of Magnetic Compass
Variation
Deviation
Inclination (Heeling)
Oscillation (Swinging)
Multiple choice
1.) Primary cause of the earth’s magnetic field
Movement of molten iron and nickel in the outer core
Multiple choice
2.) What does the term magnetic variation refer to
The difference between magnetic north and true north.
Multiple choice
3.) Which part of the magnetic compass indicates the ship’s heading
The compass card
Multiple choice
4.) What is the purpose of binnacle and magnetic compass system
To house the compass and provide an easy-to-read navigation instrument.
Multiple choice
5.) Which error in the magnetic compass is caused by the ship’s magnetic properties.
Deviation
Multiple choice
6.) What is the difference between true bearing and relative bearing
True bearing is from true north; relative bearing is from the ship’s heading.
Multiple choice
7.) Which component of the compass is used to correct the deviation caused by the ships iron and steel structures
Compass adjustment magnets.
Multiple choice
8.) What does the process of boxing do compass refers to
Correcting compass errors through known bearings.
Multiple choice
9.) Type of error is caused by the ships inclination or lift affecting the compass
Heeling error.
Multiple choice
10.) Which factor affects the heading error in a magnetic compass
Magnetic deviation.
Multiple choice
11.) Which type of compass used as the Earth rotation to determine true north
Gyro compass.
Multiple choice
12.) What is the mean advantage of using gyro compass over a magnetic compass
Unaffected by magnetic fields—provides true north.
Multiple choice
13.) What does the gyroscopic precision phenomenon cause a gyro
Compass
Maintains orientation despite ship movement.
Multiple choice
14.) Which of the following is a correct method of a gyro compass error caused by latitude
Latitude correction.
Multiple choice
15.) Which error is associated with the gyro compass if there are rapid changes in the ship course or speed
Gyro error due to rapid changes.
Multiple choice
16.) Which of the following method is used to obtain a table of deviation for a magnetic compass
Compass swinging.
Multiple choice
17.) What is the formula to correct a gyro compass error caused by speed
Depends on speed and latitude adjustments.
Multiple choice
18.) How is a deviation correcting applied in a magnetic compass
Using correction magnets during compass swinging
Multiple choice
19.) What is the term for the angular difference between true north and magnetic north
Magnetic declination
Multiple choice
20.) What is the purpose of deviation table in a ship navigation
To correct compass readings for magnetic deviations.
Essay
About compass and it’s cardinal point
A compass is a vital navigation instrument that shows direction using a magnetic needle that aligns with Earth’s magnetic field. The four cardinal points—North, South, East, and West—are crucial for determining heading and course. Intercardinal points (NE, NW, SE, SW) enhance navigation accuracy, making it easier for navigators to plot routes and maintain orientation.
Essay
Why is it important to keep a record of observe deviation
Recording observed deviation is essential for safe navigation. Deviation can cause significant heading errors, leading to dangerous situations at sea. Accurate deviation tables allow navigators to adjust compass readings, improving overall navigation safety and efficiency. Keeping a history of deviations also helps prevent future navigational errors.
Essay
Explain the meaning of gyro least, error east, gyro best and error west
Gyro Least: The minimum recorded gyro error, reflecting the best accuracy.
Error East: When the gyro reading exceeds true heading, requiring correction.
Gyro Best: The most reliable gyro reading for navigation.
Error West: When the gyro reading is below the true heading, needing adjustment for accuracy.
