Captain Jack's Complete Navigation - Softcover

Davis, Jack I.

Softcover

ISBN 10: 1892216256 ISBN 13: 9781892216250

Publisher: Bristol Fashion Publications,US, 1999

Synopsis

Captain Jack's Complete Navigation is a combination of Captain Jack's Basic Navigation and Captain Jack's Celestial Navigation. This is truly the most complete and easy-to-understand navigation package you will own. 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 also 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 navigation 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."

About this title

From the Author

PART ONE - BASIC NAVIGATION 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. PART TWO - CELESTIAL NAVIGATION

With the incredible advances in electronic navigation equipment, especially the development of the satellite system, small boat navigation is so simple I'm surprised anyone would make the effort to learn basic navigation.

The greater effort of learning celestial navigation, I thought, would be an effort that would go the way of the dinosaurs. To my surprise basic navigation is in good demand and I have more requests for classes in celestial than ever before.

There remains a fear the electronics may fail. To a greater extent my students want the security that comes with knowledge and in the case of celestial, they want the bragging rights. Very few sailors ever get far enough along with the study of celestial navigation for it to be useful to them. Most sailors at a yacht club bar will begin to fade away when a few sailors start talking about reducing sights, cocked hat star sights, etc.

Before the electronics age, most long-range sailors who claimed to know celestial navigation, only understood the "noon sight." As you will learn the noon sight is a very small part that can be learned by almost anyone in a matter of minutes.

When I decided to go cruising, I knew I had to learn celestial because the only electronic aid available at the time was the old Loran A, a huge, expensive instrument, which I knew I couldn't afford on my limited budget.

I read that people would sit on the end of a dock and learn celestial from a boat neighbor, but I didn't know anyone who knew celestial. In one sailing magazine story a new sailor picked up a book on celestial navigation and after a few hours reading was qualified to go around the world using his sextant. If it's that easy why don't I just dig in and learn? I tried not one, but several books on the subject and after many days of reading had not learned anything. During the fifth book the light finally penetrated my thick skull and I started to enjoy the learning experience. Many more days went by before I could honestly say, "I understand."

After arriving at this understanding, I spent several months getting the boat ready to go. Shortly before it was "cast off" time, I realized I couldn't remember enough celestial navigation to work a sight. To my chagrin it was almost as hard to relearn celestial navigation as it was to learn it in the first place.

Finally, all came together and I began my cruising life, with my celestial navigation working very well. This sort of life came down to a few days of sailing and weeks of hanging on the hook, gunkholing and exploring, amounting to nothing more than coast piloting. When it was time for the second leg of my cruise, I had forgotten celestial again.

All in all, I probably relearned celestial navigation six times, with each time being virtually as difficult as the first time. It wasn't until I agreed to teach celestial navigation to a group of my sailing buddies that I got the material organized well, thereby getting it straight in my mind. Using this organization as a technique in the class room I find my students are better able to remember what they learn. Part of this technique involves NOT using preprinted forms. With forms, the student is learning how to fill out forms and retains very little of the purpose behind the procedure. If the navigator addicted to forms runs out of forms or -- God forbid -- they get blown overboard or soaked with sea water, then he is no longer able to find his way. That would be no different than having a GPS with dead batteries.

Please understand my methods are not necessarily scientific perfection. They are more of a method for you to find your way with a sextant, reducing the sights on the back of a matchbook while leaning against the mast, if it is ever necessary to do so.

Excerpt. © Reprinted by permission. All rights reserved.

From Chapter 1 - First Chapter of Part One 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) From Chapter 13 - First Chapter of Part Two

The sextant will measure the height above the horizon of a celestial object, (sun, moon, planet or star), in degrees, minutes and fractions of a minute. Some sextants show seconds instead of a fraction of a minute.

What good is this to us? How does this help us find our position? To demonstrate, let's look at Polaris, the North Star.

Our latitude in Southeast Texas is about 30 degrees North. When we use our sextant to shoot a sight of Polaris we face north and find the star is about 30 degrees above the horizon. If we were in Nebraska, our latitude would be about 45 degrees North and facing north our sextant would show Polaris to be 45 degrees above the horizon. In fact if we move all the way north to the North Pole we would be at 90 degrees North latitude and our sextant would read 90 degrees height for Polaris, regardless of which direction we faced.

Therefore, we can determine our latitude by measuring the altitude of Polaris.

We can determine the distance we are away from the North Pole, by measuring the height of Polaris. The point directly below a celestial object is called the GP. The GP of Polaris "wobbles" around the North Pole every twenty-four hours, so a sextant reading at dusk will be slightly off, as will a morning reading. An average of the two readings will be exact since the morning error and the evening error offset. The nautical almanac gives corrections for both.

POLARIS

How to find it

EQUATOR TO POLE

If a sextant reading is 30 degrees, subtract that from 90 degrees, which gives the co-altitude of Polaris. In this example, that would be 60 degrees. Since each degree is equal to 60 nautical miles distance, 60 degrees times 60 miles equals 3600 miles, the distance from the North Pole.

Co-altitude x 60 miles = 3D distance away. Figure 1-1 Jack Davis

The early ocean navigators understood that you could find your latitude using the North Star.

They didn't have the very accurate sextants we have today. They had a crude instrument called an astrolabe, which would give them a rough reading. When Columbus discovered the entrance to San Juan Harbor, Puerto Rico, he knew (from the astrolabe) the entrance was at about 19 degrees North latitude. He didn't have a clue what his longitude was and for his purposes it didn't matter.

When he sailed back toward his home port, he sailed north until he arrived at the latitude of the Mediterranean entrance. There, he turned east and ran that latitude line until the Rock of Gibraltar came into view.

On his return trip to San Juan, he sailed from the Mediterranean, past the Rock of Gibraltar and sailed south to 19 degrees North. He followed that latitude line until Puerto Rico came into view.

The thousands of sailors who followed in Columbus's wake, said when leaving the Mediterranean to go to the West Indies, you sail south until the butter melts, then turn right.

This "latitude sailing" has been used by sailors (and aviators) well into the electronic age and in fact I still use the technique on occasion.

Edition details

• Publisher: Bristol Fashion Publications,US
• Publication date: 1999
• Language: English
• ISBN 10: 1892216256
• ISBN 13: 9781892216250
• Binding: Paperback
• Number of pages: 256