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Ship 468
Galveston BASE
Safety At Sea

Practice Navigation Exam

Instructions: READ CAREFULLY

Download and print the Bowditch Bay Training Chart 1998 to use for the practice exam.  This chart is best printed in black and white at 11'x17". The 2007 deviation table and the plotting and labeling standards should also be printed and used for the exam.

Fill in the blanks with the correct answer.  Show all your work and calculations. Make sure to plot to the exact BLACK DOT center of each aid to navigation.  Calculators are permitted.  Plot as if this was 1997, and use the variation to the nearest whole degree.  Your boat for this cruise is a cabin cruiser with a draft of 6.0 feet.

Plotting standards:

bulletDirection and bearings to the nearest whole degree
bulletDistance to the nearest 1/10 of a mile
bulletTime in 24 hour time to the nearest whole minute.
bulletLatitude and Longitude to the nearest 1/10 of a minute
bulletDR positions: every hour on the hour and/or change of speed or direction.

Grading Criteria:

This is a 100 point test with each question worth 4 points each.  Chart carefully because neatness counts.  Your answer must be within the following error limits:

bulletDirection and bearings within two degrees
bulletTime within three minutes
bulletDistance within 2/10 of a mile
bulletLatitude and Longitude within 2/10 of a minute

 

Name  
City, State, Zip
E-mail
Ship   Council
SEAL Course  

Time Started:            Pick a Date (Click on today's date to enter the time started)

 

You depart from the R N “2” Nun outside Perkins Cove at 0944 on a course to R “10” Q R on the left side of Channel Island.  You speed is 6.0 knots.

  1. What is your compass course? 
  2. What is your estimated time of arrive (ETA) at R “10” Q R?

 

At 1115 you notice that the R “8” I Q R aid to navigation is approximately 1 mile from you starboard side.  Concerned with your current position you decide to take hand held compass bearings on the R “8” IQR and the FL 8s 20ft 5M tower on Channel Island.  R”8” I Q R compass bearing is 081 and Channel Island FL 8s 20ft 5M tower compass bearing is 000.  Plot and label the two LOPs.

  1. What is your current Latitude?
  2. What is your current Longitude?

 

Plot and label a new course to the R’10” Q R aid to navigation from your current position.  Your speed is 5.7 knots.

  1. What is the compass course to R “10” Q R?  
  2. What is your ETA to R “10” Q R?

 

You arrive at R “10” Q R at 1200.  Depart immediately for R N “4” on the Shark River channel.  Your speed is 6.8 knots.  Plot and label your new course.

  1. What is your compass course to R N “4”? 
  2. On this course what is shallowest water depth you will encounter? 
  3. What time should you be close abeam C “1”? 

 

At 1242 your boat losses steerage, the crew stops the engine and starts to evaluate the situation.  Not able to quickly determine the problem, you decide to anchor.  You find the cause of the problem; a bolt broke on the steering cable.  The crew makes the necessary repairs and checks the steerage before proceeding.

To determine your position you take the following hand held compass bearings at 1256; FL R 6s 40 ft 10M HORN tower bears 014 and Chapman Point FL 6s 126ft 18M HORN bears 262.  Determine your position.

  1. What is your Latitude? 
  2. What is your Longitude?

 

You depart on a compass course of 097 at 1256.  Your speed is 6.8 knots.

  1. At what time will the Channel Island Fl 8s 20 ft 5M tower be starboard abeam?
  2. What would the compass bearing be (over the boats compass) to Channel Island Fl 8s 20ft 5M tower when it’s starboard abeam?  
  3. At what time would you compute your first DR from your last fix? 

 

Using only DR plotting you travel 10 nautical miles (nm) from your 1256 fix.  After traveling 10 nm according to your DR plot you change your course heading.  Plot and label a new course from this DR Mark to R N “2” outside Perkins Cove.  Your speed for the 10 nm and the change of course is still 6.8 knots.

  1. At what time will you make your course change?
  2.  What is the True course to R N “2”? 
  3. How far would you travel in 30 min at your current speed?

 

At 1500 you take the following GPS fix:

Lat 41° 41.2’ N
Lon 71° 18.8’ W

Plot and label the GPS fix.

  1. Calculate your true speed from 1424 to the 1500 GPS fix?
  2. Are you ahead or behind your DR Plot?
  3. Are you to the right or left of your course line?

 

Plot a new course from your 1500 GPS fix to R N “2”.  Your speed for the last leg is 5.7 knots.

  1. What is the compass course to R N “2”?
  2. What is the Latitude of your 1600 DR?
  3. What is the Longitude of your 1600 DR?
  4. What is your ETA to R N “2”?

 

 25. After taking this test do you feel you are ready to navigate at SEAL?
Yes
No