chap4answers


Homework Questions – Chapter 4

Homework Questions – Chapter 4

  1. Correcting a compass

    1. eliminates the effects of variation.

    2. aligns the compass lubber line with the boat keel.

    3. should be done every time you use the boat.

    4. utilizes the effects of the compensating magnets built into the compass.

    Ref:
    SG – Chapter 4, ¶ 22, 23, Compass Compensation.


  2. Compass deviation is

    1. the same for all boats in a given area.

    2. never more than 5° east or west.

    3. a factor that is unique for each boat and heading.

    4. greater in rough water.

    Ref:
    SG Chapter 4, ¶ 21, Compass Deviation


  3. A deviation table tells the navigator

    1. the number of degrees to add or subtract from true direction to obtain
      magnetic direction.

    2. the local variation in degrees.

    3. the direction of true north.

    4. the number of degrees to add or subtract from magnetic direction
      to obtain compass direction.


    Ref: SG – Chapter 4, ¶ 27, Correcting for Compass to Magnetic to True


  4. Marine compasses with no deviation will point to

    1. geographic north.

    2. true north.

    3. grid north.

    4. magnetic north.

    Ref:
    SG


    Chapter 4, ¶ 8; WN Ch 4, pg 47, Fig 4-26. 


  5. Compass deviation is caused by

    1. erratic steering.

    2. magnetic influences aboard the boat.

    3. twisting the electric wires near the compass.

    4. the magnetic attraction of the earth.

    Ref:
    SG – Chapter 4, ¶ 21, Compass Deviation


  6. Variation is 12º E, deviation is 4º W. What is the true course on a compass
    course of 065º?

    1. 081º

    2. 057º

    3. 073º

    4. 049º

    Ref:
    SG

    Chapter 4, Fig 4-1

     

7. – 9. Fill in the missing values in the table (use the Deviation Table page 62
of your Student Manual) for D [deviation] and C [compass]:

 

7

8

9

True Direction (T)

045º

106º

195º

Local Variation (V)

15º E

15º W

12º W

Magnetic Direction (M)

030º

121º

207º

Deviation (D)

4º W

12º E

5º W

Compass Direction (C)

034º

109º

212º


Ref: SG

Chapter 4, ¶ 29, Skill – Converting between Compass and Magnetic

 

10. – 20. Calculate the missing functions (use the Deviation Table page 62 of
your Student Manual) – use value of deviation from nearest direction.

 

10

11

12

13

14

15

16

17

18

19

20

True Direction (T)

056º

175º

143º

215º

330º

220º

074º

137º

005º

354º

355º

Variation (V)

12º E

5º W

5º E

10º W

12º E

8º W

15º W

3º E

15º W

15º W

15º W

Magnetic Direction (M)

044º

180º

138º

225º

318º

228º

089º

134º

020º

009º

010º

Deviation (D)

2º W

1º W

2º E

1º E

2º E

2º W

1º W

1º W

1º W

1º W

Compass Direction (C)

046º

180º

139º

223º

317º

226º

091º

135º

021º

010º

011º


Ref: SG

Chapter 4, ¶ 29, Skill – Converting between Compass and Magnetic