Captain Jack's Basic Navigation - Softcover

Davis, Jack I.

Softcover

ISBN 10: 1892216094 ISBN 13: 9781892216090

Publisher: Bristol Fashion Publications,US, 2000

Synopsis

Jack I. Davis has written this very easy to understand instructional navigation book. After traveling thousands of miles on the water and teaching hundreds of navigation and boating courses, Captain Jack has put his vast experience into this excellent book. Filled with knowledge, sea stories and humorous anecdotes, this book is not only a learning tool but thoroughly enjoyable to read. He has even thrown in a few boating lessons to help you at sea.

Captain Jack takes the reader through each phase of navigation by first explaining, in detail, the steps needed to complete each phase. This is followed by a list of questions to answer, using your new found knowledge. After you have completed the questions, you can check your answers at the end of each chapter. All the calculations are accomplished with simple, grade school math using an inexpensive calculator and basic plotting tools.

If you believe you do not need these Old Time navigational skills in this modern age of electronic navigation, Captain Jack makes this suggestion to you: "Tape a mirror below your GPS display. When the electronics fail, you can look in the mirror and see exactly who is lost". Illustrated.

About this title

From the Author

I have about 30,000 blue water sailing miles behind me plus another 5,000 blue water power boat miles. Add to that 5,000 very boring Intracoastal waterway miles and some 1,000 three or four hour sailing lessons and you can see I've spent a lot of time on boats. Most of this time has been thoroughly enjoyable.

Some of the less joyful things are storms. Storms at sea are not much fun and storms lasting for weeks at a time are not much fun for weeks at a time. We have to take the bad with the good.

When I first started to teach sailing courses, I was surprised at the satisfaction I derived from the experience. For me, there is a sense of accomplishment which didn't exist in many of my other endeavors. After going through the basics of sailing, many of my sailing students wanted to further improve their knowledge of the sea. This led me into teaching my first navigation classes.

Teaching these navigation classes was satisfying, but frustration began when I could not "get through" to many of the students. I learned that most of these "slow students" weren't slow at all. They just had an inept instructor. ME! By refining my techniques and borrowing ideas from others, I found I had fewer and fewer "slow students". This book utilizes the same techniques as a method for the reader to become a competent navigator.

The format presented here is the classroom presentation. Included is my practice of interspersing many of my sea stories with the real work. Of course, these are the same stories my former students are already more familiar with than they want to be. Many of my explanations, diagrams and procedures have come about as the most practical way for me to introduce newcomers to the navigational procedures on a boat. They may not reflect absolute scientific explanation but they will teach you what you must know.

I must admit, I've picked up many ideas and techniques from others. Too numerous to mention them all but I do want to acknowledge a few of the main ones. First, many years ago I took an "Intermediate Navigation" correspondence course from the University of Tennessee. This was my first and only venture into the academic aspects of navigation. It was a good venture, and in reviewing my teaching methods, I see the influence of that well structured course. Second, in preparing for my first U. S. Coast Guard captain's license examination, I reviewed a book by Richard A. Block, published by Marine Education Textbooks. His navigation presentation was by far the best and most comprehensive of any on the market. I know my teaching methods have been greatly affected by Mr. Block's work. Third, the number one authority on navigation, in my opinion, is Bowditch. I use both Volumes I and II extensively.

Last but not least, I must acknowledge and thank the hundreds of sailors I have sailed with through the years. I have learned something, from nearly every one of them, which influences my teaching and definitely my sea stories.
I want to especially thank Lynn Pinkerton and Sandy Billings for encouraging me to write this book and my first mate, Mary, for spelling and grammar lessons I somehow missed in school. Joe Kolb for artwork and friendship. Mike Sutton my sailboat neighbor, who worked the problems and checked the answers.

Excerpt. © Reprinted by permission. All rights reserved.

From Chapter 1: Chapter 1 DISTANCE SPEED AND TIME Being a good navigator can't be traced to one single skill. It's a composite of many talents. Today, with the availability of electronic aids, such as GPS (Global Positioning System), you could cross an ocean without the navigational talents in this book. Provided there is no electronic failure. I see inexperienced people go to sea without the proper abilities. Many make their landfall without major problems but there are some who do have complications. I talked to one of these people and his comment was, When the electronics failed, it was the most frightening experience of my life. I was not only lost, but I didn't even know where I was before I was lost. Which brings us to: Rule # 1 - Always maintain a D. R. These letters stand for Dead Reckoning. All the time you are under way, keep a record of the course, speed and the elapsed time. I can not overemphasize the importance of keeping a systematic record of your distance, speed and elapsed time, while at sea. For the electronic sailor who does not maintain a DR, I recommended he glue a mirror just below his GPS or Loran. When the electronics fail, he can then look in the mirror and see who is lost. In order to plot your course, time and speed onto your chart, you must learn to calculate distance, speed and time. Don't worry about the difficult calculations. The most complicated math involved in our navigational procedures is elementary math. As simple as it is, you should use your hand held calculator to further simplify checking the answers. Everyone does a certain amount of these calculations while driving from point A to point B. If these points are 60 miles apart and your car speed is 60 miles per hour, it's going to take an hour to make the trip. You can conclude: You're traveling one mile per minute at 60 miles per hour, in 30 minutes you will be halfway there. Navigation is that simple. In this case you are solving for distance. You know your speed (60 mph) and the elapsed time (30 minutes). The formula to solve this problem is Distance = Speed x Time. We put down 60 mph for speed and .5 for elapsed time (30 minutes is one half of an hour, or .5). Then 60 times .5 equals 30, or 30 miles, the answer to the problem. We may also need to solve for speed. This formula is: S = D / T (The / symbol represents Divided By). If we have made 30 miles in 30 minutes (.5 hours) we divide 30 by .5 which equals 60 (mph). To solve for time, the formula is T = D / S. If we have traveled 30 miles at a speed of 60 mph, we divide the 30 by 60 which equals .5 (.5 hr = 30 minutes) These formulae are critical. If you use the wrong formula, as is so easy to do, the answer will definitely be wrong. Instead of trying to remember all these formulas there is a better solution. Please be certain you understand this and do not try to remember the formulas. Always write the formula on the work paper. In the examples given for distance, speed and time, the examples were mph (miles per hour) and the distances were statue miles, used by most landlubbers. The statue mile is 5,280 feet, but the nautical mile is 6,080 feet. Everything shown from here on will be nautical miles (nm) and knots (kn). Note, I did not say knots per hour, which is incorrect. A knot is the speed of 1 nautical mile per hour. Derived from the Common Log where the number of knots (about 25 feet apart) which ran out in a quarter minute gave a direct reading of the ship's speed. Thus, if the log was streamed and six knots ran out before the quarter-minute glass ran out, the ship's speed was six knots. To say 6 knots per hour is, strictly speaking, incorrect. I use the abbreviation hr for hours and min for minutes. Remember: when you multiply or divide hours and minutes, you must convert your minutes to fractions of an hour. For instance: 2 hr 15 min must be converted to 2.25 hr (divide your minutes by 60). 15/60 minutes equals .25 hr. When you have found an answer that is hours and fractions of hours, you must convert it back: 2.25 hr must be converted to 2 hr 15 min (You multiply the fraction by 60). .25 X 60 equals 15 min. If I am using a hand held calculator, I carry all the decimal places hat the gadget will allow me to carry: 2 hr 22 min (22/60 equals .36666666). If I must use long division or multiplication (with paper and pencil), I round off to .367. The difference will be acceptable. It is important to work all of the following problems, even if you think you know how to do them. You may be surprised. The answers are at the end of this chapter. DISTANCE

SPEED

TIME 1. ____________?

7 kn

3 hr 2. ____________?

5.5 kn

4 hr 3. ____________?

13.5 kn 3.5 hr 4. ____________?

17 kn

3 hr 10 min 5. ____________?

24 kn

3 hr 10 min 6. ____________?

2.7 kn

.8 hr 7. ____________?

42.4 kn 16 min 8. ____________?

23 kn

46 min 9. 43 nm

6.2 kn

__________? 10. 32 nm

8.5 kn

__________? 11. 35 nm

12.3 kn __________? 12. 17 nm

28 kn

__________? 13. 15 nm

3.5 kn

__________? 14. 17.8 nm

29 kn

__________? 15. 6.6 nm

19.3 kn __________? 16. 8.1 nm

16.9 kn __________? 17. 22 nm

_________?

29 min 18. 23.8 nm

_________?

0.6 hr 19. 12.3 nm

_________?

19 min 20. 34 nm

_________?

88 min 21. 24.1 nm

_________?

77 min 22. 16.5 nm

_________?

0.48 hr 23. 18.9 nm

_________?

0.77 hr

24. 17.1 nm

_________?

1.5 hr In school, the stated problem was one of my least favorite problems. Life, as it turns out, is a stated problem. Certainly, navigation on a small boat is a stated problem. Don't be intimidated. Try to look at each problem as if it is a real life situation and you are the navigator in charge. 25. The distance between two buoys is 14 nm. The vessel's speed is 11 kn. The running time between the two buoys is ______________? 26. Your boat's speed is 12 kn. The speed of the current is 3 kn. What is the speed of your boat over the bottom while going upstream against the current __________? 27. Your boat's speed is 12 kn. The current's drift is 2 kn. (The speed of a current is called drift). What is the speed of your boat over the bottom as it travels downstream with the current ___________? 28. If you have a 2 kn current and can make 13 kn with a 6 nm run in each direction, how long would it take for a round trip _____________? Be certain to work this problem as two separate legs then add the results together. The answer will surprise most folks. 29. Point "B" is 59 nm from point "A" on a course of 345 degrees true. The current sets 165 degrees true at a drift of 1.7 kn. If your vessel's speed is 12.6 kn, how long will it take you to reach point "B" from point "A"____________? You already know drift is the speed of the current. Now, here is a new term: Set. Set is the direction the current is going. 30. Your course from "B" to "A" is north on a leg of 10 nm. Your boat's speed is 10 kn. The current's set is 180 degrees with a drift of 4 kn. What is your speed over the bottom ____________? 31. Your vessel is making way through the water at a speed of 13 kn. Your vessel traveled 30 nm in 4 hr 23 min. What current are you experiencing ___________? DISTANCE SPEED TIME ANSWERS 1. 7 kn x 3 hr = 21 nm 2. 5.5 kn x 4 hr = 22 nm 3. 13.5 kn x 3.5 hr = 47.25 nm 4. 17 kn x 3.1666666 = 53.8333 nm 5. 24 kn x 3.16666 hr = 75.9 nm 6. 2.7 kn x .8 hr = 2.16 nm 7. 42.4 kn x .266666 hr = 11.30666 nm 8. 23 kn x .7666666 = 17.6333 nm 9. 43 nm / 6.2 kn = 6.9354838 hr or 6:56 hr & min 10. 32 nm / 8.5 kn = 3.7647058 hr or 3:46 hr & min 11. 35 nm / 12.3 kn = 2.8455284 hr or 2:51 hr & min 12. 17 nm / 28 kn = .6071428 hr or 0:36 min 13. 15 nm / 3.5 kn = 4.2857142 hr or 4:17 hr & min 14. 17.8 nm / 29 kn = .613793 hr or 0:37 min 15. 6.6 nm / 19.3 kn = .341968 hr or 0:21 min 16. 8.1 nm / 16.9 kn = .4792899 hr or 0:29 min 17. 22 nm / .483333 hr = 45.517 kn 18. 23.8 nm / .6 hr = 39.666 kn 19. 12.3 nm / .316666 hr = 38.842 kn 20. 34 nm / 1.4666666 hr = 23.1818 kn 21. 24.1 nm / 1.2833 hr = 18.779 kn 22. 16.5 nm / 0.48 hr = 34.375 kn 23. 18.9 / .77 hr = 24.545 kn 24. 17.1 nm / 1.5 hr = 11.4 kn 25. 14 nm / 11 kn = 1:16 hr & min 26. 12 kn - 3 kn = 9 kn 27. 12 kn + 2 kn = 14 kn 28. Work as two legs:

1st leg 6 nm - (13 - 2) = .54545

2nd leg 6 nm - (13 + 2) = .40000

.94545 hr The temptation in this problem is to reason that the current coming and going balances out. Therefore, you could simply use 13 kn = 0:55384 min which will not provide the correct answer. 29. Then:

59 nm / 10.9 kn = 5.41284 hr

Then:

.41284 X 60 = :247706 min = 5 hr 25 min 30. The course - North (360 degrees)

The current sets South (180 degrees)

Speed 6 kn 31. 30 nm - 4.383333 hr = 6.844111 kn (Speed made good) Then:

Boat speed 13 kn

less 6.8441111 (speed made good)

drift 6.155889 (speed of current)

Edition details

• Publisher: Bristol Fashion Publications,US
• Publication date: 2000
• Language: English
• ISBN 10: 1892216094
• ISBN 13: 9781892216090
• Binding: Paperback
• Number of pages: 132