NAVIGATIONAL AIDS – QUESTION BANK

MAGNETIC COMPASS

1. IMO Performance Standards

2. What type of Magnetic Compass would you choose for a new ship & where should it be placed?

3. Function of Flinders bar & how does it act?

4. Why is the ship swung & compass compensated instead of being swung & deviation noted on each

heading?

5. Probable cause for change in variation.

6. Effects of gaussing error, errors due to sub-permanent magnetism on ship’s magnetic compass

during compass adjustment.

7. Process of deflector method of compass adjustment (2).

8. Method of obtaining deviation table / curve.

9. Labeled diagram of compass binnacle.

10. Vessel alongside Berth #1, flinders bar is removed & deviation remains unchanged. Vessel shifted

to Berth #2, flinders bar is replaced & deviation changes. Give reasons.

11. Sequence of compass correction with reasoning.

12. Tentative method of compass adjusting.

13. Onboard your vessel you have noticed that soft iron spheres are attached to the binnacle in relative

slewed direction, i.e. 280° - 100°. Analyse & discuss in details the reasons for such an

arrangement. What would have been the ship’s heading on which maximum deviation would have

occurred prior to soft iron correction?

GLOBAL POSITIONING SYSTEM

1. IMO performance standards for GNSS/GPS (2)

2. Outline of GLONASS & GALILEO

3. Explain datum shift.

4. Explain sources of error in GPS & approximate values. (5)

5. Explain principle of DGPS & how accuracy is enhanced. (2)

6. Explain alarms of GPS.

7. Explain working of GPS in calculating position & speed. (2)

8. Explain navigation data message, its significance & contents. (2)

9. Explain geocentric co-ordinate system PZ90.

GYRO COMPASS

1. IMO Performance Standards

2. Operating principle & care of Gyro

3. Settling Error.

4. Explain why gyro compass never settles in a horizontal position unless gyro is located at the

equator.

5. What is ballistic deflection? Explain how error due to ballistic deflection can be obtained by

Schuler tuning?

6. Schuler Period & Schuler tuned gyro.

7. Derive expression for Course, Latitude & Speed Error.

8. Principle & causes of heeling error. How does error change with latitude, course & heel?

9. Course & speed error & how does it affect the settling position.

10. Care & maintenance of gyro.

11. Differentiate between ballistic deflection & ballistic tilt.

12. Method of converting a free gyroscope into a gyro compass. Method of control.

13. Inter-cardinal rolling error & how is it taken care of?

ECHO SOUNDER

1. IMO Performance Standards (3)

2. Explain principle & working of echo sounder

3. Explain errors of echo sounder (2)

4. Explain ranging & phasing

5. Explain phasing technique to determine depth.

6. Explain effect of density, temperature, pressure on velocity of sound & accuracy.

BRIDGE NAVIGATIONAL WATCH ALARM SYSTEM

1. IMO Performance Standards

2. Carriage requirements

3. What is the function of BNWAS? (2)

4. Write a short note on BNWAS.

5. Working requirements of BNWAS

6. Different levels of alarms

AUTO PILOT

1. IMO Performance Standards.

2. Regulations regarding use of Auto - Pilot

3. Functions of adaptive auto-pilot system

4. Optimum settings for steering a ship on auto pilot. (2)

5. Entries to be made on course recorder paper.

6. Sketch & describe PID controls.

7. Common controls of auto pilot.

8. Working of auto pilot with diagram.

AUTOMATIC IDENTIFICATION SYSTEM

1. IMO Performance Standards.

2. Carriage requirements (2)

3. Purpose & working principle. (3)

4. Contents of navigation message & static message (3)

5. Information displayed.

6. Differentiate between Type – A & Type – B AIS. (2)

7. Limitations & advantages. (3)

8. Mandatory testing requirements.

9. Information from AIS should not be used for collision avoidance.

10. Time interval

11. Parts of AIS message & transmission schedule.

12. Pseudo AIS

ELECTRONIC CHART DISPLAY & INFORMATION SYSTEM

1. IMO Performance Standards. (2)

2. Requirements of ECDIS & its back up arrangements

3. Advantages of ECDIS over paper charts. (2)

4. Differentiate between raster charts & vector charts.

5. How are charts corrected on ECDIS?

LONG RANGE IDENTIFICATION & TRACKING

1. IMO performance standards

2. Purpose & working principle. (2)

3. Differentiate between AIS & LRIT (2)

4. Data transmitted by LRIT.

VOYAGE DATA RECORDER

1. IMO Performance Standards.

2. Short note on VDR & S-VDR. (3)

3. Modules of VDR & procedure for saving & retrieval of data. (3)

4. Information that needs to be recorded. (4)

RATE OF TURN INDICATOR

1. IMO Performance Standards (2)

2. Procedure to execute a constant radius turn with / without current. (2)

3. Controlled radial steering. (3)

4. Plan a turn of 70° using ROTI on a VLCC of 350,000 DWT. Describe formula used.

5. Factors to consider when choosing radius of turn. (2)

6. Advantages & disadvantages of Constant Radius Turn & Constant Rudder Angle Turn.

SPEED LOG

1. IMO Performance Standards. (2)

2. Working principle of Doppler Log. (3)

3. Sources of error in Doppler Log. (3)

4. Janus configuration & its working principle

5. Working principle of electromagnetic log & its errors.

6. Doppler shift.

NUMERICALS

1. Radar plotting

2. Gyro compass

3. Constant Radius Turn