Marie

Question 1

What is bearing in navigation?

Answer 1

The horizontal direction of one terrestrial point from another, expressed in degrees.

Question 2

What are the three different types of bearing?

Answer 2

• True bearing
• Compass bearing
• Relative bearing

Question 3

Define true bearing.

Answer 3

The direction of an object or point in relation to true north, measured in degrees from 0° to 360°.

Question 4

Define compass bearing.

Answer 4

The direction of an object or point taken with the compass, measured with respect to magnetic north.

Question 5

What is relative bearing?

Answer 5

The direction of an object in relation to the current heading of a vessel, measured from 0° to 360°.

Question 6

How is relative bearing measured?

Answer 6

From 0° to 360°, with 0° being dead ahead.

Question 7

What is the function of an azimuth circle?

Answer 7

A device for measuring azimuths, consisting of a graduated ring equipped with a sighting vane.

Question 8

What is a telescopic alidade?

Answer 8

A bearing circle with a telescope attached to the metal ring.

Question 9

What is a pelorus?

Answer 9

A device for measuring in degrees the relative bearings of observed objects.

Question 10

What is the formula to calculate gyro error?

Answer 10

Gyro Error = Gyro Heading - True Heading (based on quay line)

Question 11

What is the acceptable limit for determining gyro error?

Answer 11

+/- 0.1 degree.

Question 12

What steps are involved in determining gyro error?

Answer 12

• Observe the quay line
• Read the gyro heading
• Estimate true heading
• Calculate the gyro error
• Interpret the error

Question 13

When is a gyro compass considered fast?

Answer 13

When the gyro error is positive.

Question 14

When is a gyro compass considered slow?

Answer 14

When the gyro error is negative.

Question 15

What is cross bearing?

Answer 15

The bearing of two or more objects used as intersecting lines of position for fixing the position of a craft.

Question 16

How do you convert from compass to relative bearing?

Answer 16

Relative Bearing = True Bearing - Ship Heading.

Question 17

If a vessel is heading 120° and a cruise ship bearing is 070°, what is the relative bearing?

Answer 17

310°.

Question 18

If a vessel is heading 120° and a sailing vessel bearing is 240°, what is the relative bearing?

Answer 18

120°.

Question 19

What is the true bearing of a ship sighted at a relative bearing of 090° while the ship is headed south?

Answer 19

270°.

Question 20

What is the significance of variation in marine navigation?

Answer 20

It is the difference between true north and magnetic north.

Question 21

What must be ensured when observing the quay line for gyro error determination?

Answer 21

The ship must be fully stationary to avoid drift.

Question 22

What is the true heading if the quay line is aligned to 166° T and the gyro heading shows 165.3°?

Answer 22

Gyro error = -0.7°.

Question 23

What is the true heading if the quay line is aligned to 221° T and the gyro heading shows 221.4°?

Answer 23

Gyro error = +0.4°.

Question 24

What is the true heading if the quay line is aligned to 359° T and the gyro heading shows 000.8°?

Answer 24

Gyro error = -358.2°.

Question 25

What is the formula for determining true bearing if the ship’s heading is known?

Answer 25

True Bearing = Relative Bearing + Ship Heading.