Chapter 1: Introduction to Navigation

1. Navigation Study Guide Chapter 1: Introduction to Navigation Instructor: Walter Spall All Questions from the Study Guide PowerPoint Presentation by Forrest Meiere

2. Navigation Study Guide S1-1. In simple terms, marine navigation is ____________________________________________ _____________________________________________. getting your vessel from where you are to where you want to go, safely & efficiently S1-2. Coastal navigation refers to ________________ ___________________________________________ ___________________________________________. navigation in coastal waters where there are navigational aids for reference in determining the vessel’s position S1-3. It is convenient to subdivide navigation into two distinct phases, _______________________ _______________________. voyage planning and underway navigation

3. Navigation Study Guide S1-4. The steps in voyage planning include: Assemble reference materials. Formulate & evaluate alternatives. Select and prepare float plan. Complete pre-underway checks. Weigh Anchor. S1-5. For the purposes of this course, the earth is a ________ with an average diameter of _______ miles and a circumference of ________ miles. sphere 6,888 21,614

4. Navigation Study Guide S1-6. The process of predicting the future position from knowledge of its present position, course steered and speed is termed ___________________. dead reckoning (DR) S1-7. The earth revolves about an axis passing through the earth’s center and intersects the surface at two points, termed ______________________________. north and south geographic poles S1-8. A plane passing through the earth’s center intersects the surface to produce a ____________. great circle

5. Navigation Study Guide S1-9. On the surface of a sphere, the shortest distance between any two points lies on a ____________ connecting them. great circle S1-10. If a plane passing through the earth’s center is perpendicular to the axis of rotation, it forms a great circle termed the _________. equator S1-11. The upper branch of the great circle passing through the poles and Greenwich, England is called the ____________________________________. prime meridian or Greenwich meridian

6. Navigation Study Guide S1-12. A circle contains ____ degrees. Degrees are subdivided into ________ and ___________________________. 360 minutes seconds or tenths of minutes Longitude S1-13. __________ (Lo) is the angle between a position on earth and the prime meridian measured east or west. S1-14. A plane passed through the earth that does not touch the earth’s center forms a ___________ on the surface. small circle

7. Navigation Study Guide S1-15. The angle between a position on earth and the equator measured north or south is _______________________. Latitude or Lat or L S1-16. Any position on the earth’s surface can be defined by specifying its ________ and __________. latitude longitude latitude longitude S1-17. One degree of _________ equals 60 nautical miles. Not so for _________ except at the equator.

8. Navigation Study Guide S1-18. Three common ways to specify direction are ___________________________. true, magnetic, compass S1-19. When a course crosses each meridian at the same angle the resultant line is called a ____________ or ____________. rhumb line loxodrome weak magnetic field S1-20. The earth has a __________________, thought to be generated by the flow of the liquid iron alloy core of the planet. (A little more complicated than this; FM)

9. Navigation Study Guide S1-21. At the surface of the earth, lines of magnetic field are termed, __________________ analogous to __________ meridians. (magnetic field, not force) magnetic meridians geographic S1-22. The angle between geographic and magnetic meridians is called _________________ or _________. magnetic variation variation east S1-23. Variation is said to be _____ if the magnetic meridian points east of geographic north.

10. Navigation Study Guide S1-24. Lines of constant variation are termed _________ and the line of zero variation is termed the ______ line. isogonic agonic S1-25. Conversion from magnetic to true direction involves ________ east variation and ___________ west variation. adding subtracting. .(Don’t remember it this way. FM) S1-26. To convert from relative bearing to true or magnetic use the equation: _____________ + ______________ = _______________. If this exceeds _____, subtract ______. ship’s heading relative bearing object’s bearing 360° 360°

11. Navigation Study Guide S1-27. An object off the stern has a relative bearing of ____ while one directly off port has a relative bearing of _____. 180 270 outer circle true inner circle magnetic north S1-28. Normally, the ___________ of the compass rose references _____ north while the ____________ references ______________.

12. Navigation Study Guide 20W zero 21E . 35E S1-29. Variation ranges from _____ in Maine, through ______ in Florida to _____ in Washington. In Alaska, it can be as large as ______. S1-30. A handy rule to remember in converting from magnetic to true is “magnetic to true, add _____.” East (While this is correct, don’t use it as a “rule”. FM)