Chartwork  # 3

Additional Questions on Magnetic, or Compass Courses

Refer to your chart: “Western Long Island Sound” and apply what you learned in:

 

Chapter #9

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1.  Find the Compass Rose that is printed in Mid-Sound on your chart.

Note the Variation, its date and the rate of change.    Recognizing that our chart work will be conducted using whole degrees (i.e. rounding off the minutes to a whole degree), please indicate the value for Variation that you will use for this year’s chart work.

                        Is it    12°W     13°W     14°W   or     15°W  ?                                 __________°W

 

 

2.  There are several more Compass Rose diagrams to be found on the detail harbor charts on the reverse of the main chart.  Do they all have the same value for Variation?  (For this question you SHOULD look at the minutes, just for comparison among the different detail charts).  Are they exactly the same?                                                             __________

 

 

3.  Note the values shown for Variation in the detail charts for the vicinity of:  City Island, Huntington, and Port Jeff.  (Again, in this question , consider the value for the degrees and minutes)  What pattern do you notice?  Could you offer a generalization about what happens to Variation as you proceed to the East?    Would you expect Variation at your summer cruising destinations far to the East (Block Island, Martha’s Vineyard and Nantucket)  to be less than, or greater than the Variation that is shown for this area?             __________

 

 

4.  The answers for the three courses that you plotted last week were given as TRUE - that is, exactly as plotted on the chart.  Now, while taking into account the rule:

“WHEN GOING FROM TRUE TO COMPASS (MAGNETIC) ADD WESTERLY VARIATION”

please revisit the three questions from last week - and determine the Compass course that you would follow if you were to travel from:

 

                                                                                                                        TRUE              MAGNETIC

 

4.1  Darien’s G”1” to G”1” Fl G 2.5 sec at Eatons’ Neck              _________°  ________°

 

Your return trip would be (the reciprocal)                                                    _________°  ________°

 

 

4.2  Darien’s G”1” to G”15”  GONG,  North of Lloyd Point                       _________°  ________°

 

Your return trip would be (the reciprocal)                                                    _________°  ________°

 

 

4.3  Smith Reef R”30” to Stamford’s R “32” at The Cows                        _________°  ________°

 

Your return trip would be (the reciprocal)                                                    _________°  ________°