Navigation Exercise – Mountaineers Sailing Class

Here are the questions and answers for the Mountaineers Sailing Crew Class Navigation Exercise There is a Chartlet with the answers drawn on it.

The answers match the Chartlet handed out in class.  If you misplaced or did not receive a Chartlet there is one at the bottom of the page.  The Chartlet provided here is slightly different from the one furnished in class.  This one has depths in feet and slightly smaller type in some areas.

Reference card with help for correcting and uncorrecting a compass, speed / time formulas and other quick hints for navigators.

Navigators Piloting and Charting Reference Card

More Navigation Exercises & Practice:

Crew Course Navigation Exercise 1

Navigation Exercise 2 

Mountaineers Sailing Crew Class Navigation Exercise



The following questions can be answered by referring to the marine chart and the tide table attached. They represent typical types of information you may need to know when on the water.

Situation A:

1) You are out sailing and the fog sets in and you cannot see land. Your GPS shows your position as:

Lat.       47° 41.1′ N     (47° 41′ 06″ N)
Long. 122° 26.0′ W  (122° 26′ 00″ W)

Find your position on the chart.

2) You want to head to shore. How would plot a course?

3) You have determined that you want to go on a course of 090° Magnetic.

What navigational marker will you see first?

4) It is still foggy, how will you be able to locate this marker if you cannot see it?

5) In addition to your compass and GPS, what instrument can you use to determine where you are in relationship to shore?

Situation B:

1) You have come through the locks on a clear sunny day (5/21/05) and you want to go south. It is 10:008am.

What will you see if you turn south at N “6”?
What will your depth sounder read?

2) Same situation, but it is 4:00PM.

What will you see?
What will your depth sounder read?

Situation C:

1) It is nighttime and you are approaching West Point from the south. You see a flashing yellow light every 4 seconds.

Find the light on the chart.

2) You see a flashing green light. Where is it? How often is it flashing?

3) What would you look for to identify the West Point lighthouse?

4) You are still south of West Point, now sailing North. Your depth sounder reads 24 feet and it is low tide.

Approximately where are you?
Do you need to change course?

Excerpt from tide table for Seattle for 5/21/05:

5/21/05 10:07 AM PDT   -0.04 feet Low  Tide
5/21/05  5:06 PM PDT    9.97 feet High Tide

Answers:

Navigation Answer Chart



Situation A:

1) About at the edge of the shipping lane between 45 and 60 fathoms

2) Use the compass. Read Magnetic rose.

3) RW MO(A) (Morse “A”)

4) It has a bell

5) Depth Sounder

Situation B:

1) About 00 ft. You” be aground

2) About 10 to 12 feet. It will look like there is plenty of water. but the chart shows the area next to the shore as drying at low tide (e.g. it is brown). The light blue color means it is shallow. The chart is in fathoms (6 feet) so 0 sub 2 means two feet).

Situation C:

1) It is the mid-channel marker SG and is Y = Yellow.

2) G -1- off West Point. Green every 4 seconds.

3) White and red flashes on 10 second intervals, alternating.

4)You are in the 6-fathom line just outside of the light blue area) and the water is getting shallower. It will soon drop to about. 16 feet as you cross into the 4-fathom contour. Your choice about. changing course for a short distance.

Formatted for Printing Questions and Answers (PDF)

New Worksheet for Navigation Exercise (PDF)





Additional Navigation Sheets Section of Chart 18446 Showing West Point & Shilshole Bay:

18446-West-Point-11×17 (PDF) (500k)
18446-West-Point-17×22 (PDF) (500k)

– c/m –

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