1. Name:
INTRO TO NAVIGATION PART 2
1. On nautical charts, what units are used to show the depth of water?
2. How many feet is one fathom?
3. An accurate position determined without use of any previous position, using visual, electronic,
or celestial observation is called what?
4. A line indicating a series of possible positions of a ship as a result of observation or
measurement is called what?
5 What is the term used when two landmarks or navigation aids are observed in line one behind
the other?
6. What instrument determines the distance to an object optically using as a reference the
distance to an object of known height such as a masthead on a ship?
7. What do you call the intersection of two or more lines of position (LOPs) obtained at the same
time?
8. What do celestial navigation systems use to determine fix locations?
9. What are the three most commonly used ways to obtain a fix?
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10. What symbol is commonly used on nautical charts to plot the following ship’s position?
• A visual fix -
• Electronic/Celestial Fix –
• Dead Reckoning Position -
• Estimated position -
11. The determination of position and directing the movements of a ship by landmarks, constructed
navigational aids, or water depth readings made by a fathometer is called what?
12. What instrument determines the depth of water under the ship’s keel?
13. What would be the depth of the ocean floor if a sounding sent out from a depth finder took
1/10 of a second to return?
14. What are the advantages of Electronic Navigation?
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15. What are the disadvantages of Electronic Navigation?
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16. What is the primary disadvantage of radar, as a navigational aid?
17. When using radar for electronic navigation, what type of display scope is most often used?

2. 18. Advantages of using radar as a navigational aid include:
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19. A navigational system made up of radio signals broadcast by groups of land-based transmitting
stations at known positions is called what?
20. system is rapidly replacing the systems of Loran transmitting stations?
21. How many satellites make up the GPS system?
22. What is the accuracy of the basic GPS system?
23. What is differential GPS and what is its’ accuracy?
24. What system gives ships an accurate and continuous dead reckoning position using three
gyroscopes to determine latitude, vertical, and longitude with great accuracy?
25. What does SINS stand for?
26. What is the branch of navigation in which position is determined by the aid of heavenly bodies
such as the Sun, Moon, and selected stars and planets called?
27. What device is used in celestial navigation to measure the angle (altitude) between a heavenly
body and the visible horizon?
28. Calculation of one's position on the basis of distance run on various headings since the last
precisely observed position, with as accurate allowance as possible being made for wind,
currents, compass errors is called what?
29. Draw the symbol used for the following:
• Visual Fix
• Electronic/Celestial Fix
• Dead Reckoning Position
• Estimated Position
30. The direction in which a ship is forced by wind and current is called
The speed of that force in knots is called
31. At sea, how often will the navigator will use celestial or electronic means to get positive fixes?