This lesson deals about the overview of Navigational Instruments with Compasses.

The topic state the purpose of each electronic navigational aids and describes the reference for position fixing and the student will familiarizes with the different navigational bridge equipment

It describes the basic operating principles of Loran-C and eLoran system, advantages and limitations of eLoran and how to selects chain, relates the time differences obtained to the correct station pair and system faulty warnings.

This topic deals with the earth’s coordinates (latitude, longitude, equator, Greenwich) and describes the principles of reading and interpreting the chart scales

This topic describes the principles of operation of global navigation satellite systems (GNSS). States that the system will provide continuous worldwide position-fixing capabilities. Describes the intended level of accuracy of the system

This topic describes the basic principles, system configuration, frequencies of the Global Positioning System (GPS). Describes the basic line measurement, Dilution of Precision (DOP) selective availability, and the effect it may have on the accuracy of a fix and various errors of GPS. Describes the accuracy obtainable with GPS and how the accuracy can be downgraded.

This topic explains WGS 84, and why a fix obtained from the GPS receiver cannot be plotted direct onto a navigational chart. Distinguishes the advantages and limitations of GPS.

It describes the basic principle of Differential GPS, DGPs, and the Regional satellite Navigation systems

This topic describes the principle on which the GLONASS works, and the advantage of the receiver capable of operating both GLONASS and GPS “combined.

This topic describe that Galileo comprises 30 medium earth orbit (MEO) satellites in 3 circular orbits. State the satellite geometry and dual atomic clocks in the Galileo system.

This topic explain the basic principles of Automatic Identification System, advantages, limitations and importance of AIS to navigation. Identify the parts and functions of AIS Equipment

This topic explains the basic setting procedures of AIS. Identify the information obtained by the AIS equipment

this topic describes the basic principles of marine echo-sounding equipment, its physical factors which affect the sound velocity in seawater and the accepted value.

Distinguish between inaccuracies caused by instrument and scale error, false echoes, inaccuracies to instrument or scale error and other potential errors due to trim, heel and transducer separation Recognize the various types of “false” echo that may be observed, their formation and possible action to remove them from the trace.

Appraise the accuracy of readings from echo-sounder

Explain the theory of magnetism.

Describe the effect of introducing a disturbing magnetic force into the vicinity of a compass needle and the needle will align itself with the resultant field. Explain the direction and strength of a magnetic field may be represented by a vector.

Explain ‘magnetic variation’ and why it is a slowly changing quantity and whereit can be found.

Describes the basic principles and construction magnetic compass. Describes how to check that the card is turning freely on its pivot and how the compass bowl is supported in the binnacle with the arrangement of correcting. devices

Describe the composition of the liquid, the allowance for changes in volume of the liquid and how to remove the air bubble from the compass bowl. Explain the need for care in the placing of portable items of magnetic material, including spare corrector magnets, or electrical equipment in the vicinity of compasses.

Explain the importance of regular checking and after major course alteration of the compass error. Explain why regular comparisons of standard compass, steering compass and gyrocompasses should be made Explain that the approximate error of the standard compass can be obtained by comparison with the gyrocompass if no other means is available

Describe a free gyroscope and its gimbal mountings. Describe the precession resulting from a torque about axes perpendicular to the spin axis and the friction at gimbal pivots produces torques which give rise to precession.

Describe a free gyroscope and its gimbal mountings. Describe the precession resulting from a torque about axes perpendicular to the spin axis and the friction at gimbal pivots produces torques which give rise to precession.

Explain starting of the gyrocompass, how to minimize settling time by slewing and levelling it to the correct heading and the necessary time for the compass to settle after switching on prior to sailing. Operate gyro compass

Define single axis and dual axis. Explain basic operation of fluxgate compass. Explain Transmitting Magnetic Compass (TMC) System. Describe solid state type fluxgate compass

This topic defines true, magnetic and compass north. Explains how to find deviation and variation from tables and charts. Calculate true course from compass course and vice-versa.

This topic appraises the compass error calculations using a transit bearing.

This topic explains the procedures in taking compass bearing of a charted object and lays the true bearing off on the chart.

This topic explains how the magnetic variation for the observer’s position obtains, using isogonal lines or other information on the chart. Apply variations to the error of the magnetic compass to find the deviations for the direction of the ship’s head.

This topic explains the procedures in calculation of compass error and gyro error from transit or range lights and bearings of distant fixed objects. Calculate compass error and gyro error, from transit or charted range bearings and bearings to distant fixed objects

Identify the required information and process of finding amplitude of celestial (from tables or by calculation), using the observer’s DR position and information from the Nautical Almanac, the true bearing of a heavenly body on rising or setting.

Final Examination