MCA CoC Navigation & Chart Work

Question 1

What is the difference between True North, Magnetic North, and Compass North?

Accepted Answer

True North is geographic north; Magnetic North is where the compass points due to the Earth's field; Compass North includes instrument deviation

Answer

True and Magnetic North are the same; Compass North differs

Answer

True North is the compass direction; Magnetic North is geographic

Answer

All three are identical in UK waters

Question 2

What is 'variation' on an Admiralty chart?

Accepted Answer

The angular difference between True North and Magnetic North at a given location and time

Answer

The difference between compass heading and steered course

Answer

The error introduced by the ship's metal structure

Answer

The difference between chart datum and sea level

Question 3

What is 'deviation' in compass navigation?

Accepted Answer

The error in a ship's compass caused by the vessel's own magnetic field and ferrous material on board

Answer

The difference between true and magnetic north at a location

Answer

The error caused by rough weather affecting the compass card

Answer

The angular difference between the bow and the ship's head

Question 4

A vessel's compass reads 045°C and deviation for the heading is 3°W. What is the Magnetic heading?

Accepted Answer

042°M

Answer

048°M

Answer

045°M

Answer

038°M

Question 5

What is a 'fix' in coastal navigation?

Accepted Answer

A positional determination obtained by crossing two or more position lines from observed bearings, landmarks, or electronic systems

Answer

An estimated position based on DR only

Answer

A satellite position used to update the chart

Answer

A depth sounding that matches the chart

Question 6

What is the purpose of a 'running fix'?

Accepted Answer

To obtain a position using two bearings of the same object taken at different times, with the ship's track run up between them

Answer

To plot the fastest route between two waypoints

Answer

To calculate speed through the water from the ship's log

Answer

To determine the current set and drift