Navigation

Answers to Mini-Chart Lesson 2

Chris Riley by Chris Riley Updated on August 16, 2019. In navigation

Coastal Navigation Course
Chapter IX

Answers to Mini-Chart Lesson 2

Question 1 – Steps & Calculations:

  1. Find Easton Point. If you had a Coast Pilot it would be helpful.

  2. Convert the Magnetic bearing to True direction.
    044 M – 14 W = 030 T

  3. Plot this true LOP from Easton Point by finding 030 T on your compass rose and walking the parallel rules until you get to Easton Point. Since the question tells you that you are on a range of 1.9 nm, draw the line a little longer than that. (I like to draw LOP lines as dashed lines. This way I don’t confuse them with course lines.)

  4. Use your dividers to find 1.9 minutes of latitude on the latitude scale.
    1.9 min = 1.9 nm

  5. Measure this distance along the LOP line and mark that location.

  6. Find the latitude and longitude of this location.

Question 2 – Steps & Calculations:

Helpful Hint: If you don’t have a regular compass to draw arcs or a set of dividers with the ability to hold pencil lead in one leg, simply tape a small pencil to one leg of your parallel rules so that its point is even with the pin.

  1. Find Beavertail Point and Brenton Reef Light. Again, a Coast Pilot and Light List might come in handy.

  2. Using your dividers with a pencil or a compass, find the distance of 2.0 nm on the latitude scale. Using that span of the dividers, put the point on Beavertail Point. Swing a small arc with the “pencil” leg in the area SW of Brenton Reef Light.

  3. Next, again using the latitude scale find a distance of 1.5 nm.

  4. Put the point of the dividers on Brenton Reef Light and draw a small arc SW of the light. Where this arc crosses the arc from Beavertail Point is your location.

  5. Find the latitude and longitude of this location.

Question 3 – Steps & Calculations:

  1. Find Easton Point, Brenton Reef Light and the spire on Easton Point.

  2. Convert the Magnetic bearing to Brenton Reef Light to True direction.
    254 M – 14 W = 240 T

  3. It is not necessary to convert the direction to the spire since it is given in True.

  4. Plot this true LOP from Brenton Reef Light by finding 240 T on your compass rose and walking to Brenton Reef Light. Be sure to draw your LOP in the correct direction.

  5. Plot the second bearing of 030 T from the spire on Easton Point. Where these two LOPs cross is your position.

  6. Find the latitude and longitude of this location.

Question 4 – Steps & Calculations:

  1. Find Brenton Reef Light and the cupola on Brenton Point.

  2. Convert the Magnetic bearing to Brenton Reef Light to True direction.
    214 M – 14 W = 200 T

  3. Convert the Magnetic bearing to the cupola to True direction.
    104 M – 14 W = 090 T

  4. Plot this true LOP from Brenton Reef Light by finding 200 T on your compass rose and walking to Brenton Reef Light. Be sure to draw your LOP in the correct direction.

  5. Plot the second bearing of 090 T from the cupola. Where these two LOPs cross is your position.

  6. Find the latitude and longitude of this location.

Question 5 – Steps & Calculations:

  1. Find the silo on Sachuest Point, the western most part of Church Point and the abandoned Light House Tower on Sakonnet Point.

  2. Convert the Magnetic directions to True directions.
    344 M – 14 W = 330 T (silo)
    044 M – 14 W = 030 T (western most part of Church Point)
    124 M – 14 W = 110 T (Light House Tower)

  3. Plot these three LOPs on your chart. Where all three cross is your location. In real life, because you are probably moving while taking bearings, three bearing fixes may not all cross exactly in one location but form a small triangle. Your position should be assumed to be in the center of this triangle.

  4. Find the latitude and longitude of this location.

[mashshare]

Categories:

Tags:

Leave a Reply

Your email address will not be published. Required fields are marked *