Coastal Navigation Course
Chapter X

Answers to Mini-Chart #3 Lesson - ETA

These questions can be a little tricky. The main reason is that you are given lots of extraneous information that is not needed. Don't try to overthink the question or read into what is being asked. Each question asks you to use the set and drift information from a previous exercise. It does not ask you to use any other information such as course made good or course to steer. Actually, the only set and drift information you will need is the Speed Made Good (SMG) ignore everything else.

You may be asking, why write questions that are so confusing? The answer is, for those of you that may be taking the course to prepare yourself to take the USCG Captains License exam, these are exactly the kind of questions you will encounter.

Question 1 - Steps & Calculations:

1. Find your 1000 position.

2. Draw your 020° T course line to Marker W "2" at Dry Ledge.

3. Measure the distance from your 1000 location to the Marker. You should get 4.1 nm.

4. Now you have a simple DST problem with one exception instead of using your boat speed, you are going to use the 6.2 SMG from question 6 of the previous exercise.
   4.1 Distance / 6.2 SMG = .66 hours
   .66 X 60 = 39.6 or 40 minutes
   1000 + 40 = 1040

Question 2 - Steps & Calculations:

1. At 1045 you leave marker W "2".

2. Draw your course line toward Nyes Neck Tower (TR). This line should be approximately 152° T.

3. Find the location of the point 0.6 nm NNW (approximately) of Nyes Neck Tower in 15 feet of water and measure the distance to this point. You should get 3.5 nm. (Note: approximately NNW does not mean exactly NNW)

4. Now you have a simple DST problem with one exception instead of using your boat speed, you are going to use the 3.4 SMG from question 5 of the previous exercise.
   3.5 Distance / 3.4 SMG = 1.03 hours
   .03 X 60 = 1.03 or 1 hr 2 minutes
   1045 + 0102 = 1147

Question 3 - Steps & Calculations:

1. At 1200 you leave point found in the previous question.

2. Draw your course line toward daymarker R "2A" off Angelica Point. This line should be approximately 263° T.

3. Measure the distance to this point. You should get 4.8 nm.

4. Now you have a simple DST problem with one exception instead of using your boat speed, you are going to use the 3.0 SMG from question 4 of the previous exercise.
   4.8 Distance / 3.0 SMG = 1.6 hours
   .6 X 60 = 36min or 1 hr 36 minutes
   1200 + 0136 = 1336

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