TIME AND NAVIGATION
1. What is time based on?
2. What is the name given to navigational timepieces designed for extreme accuracy and
3. Once started, when are chronometers allowed to stop?
4. Radio stations in two locations broadcast time signals every five minutes to help mariners
maintain accurate time at sea. Where are these radio stations located?
5. Setting the ship’s clock to the correct time, so that everyone aboard is using accurate time
for log entries and messages is a job assigned to who?
6. What do the term’s AM and PM stand for?
7. Why does the military use a 24 hour clock?
8. While 0000 and 2400 are exactly the same time, it is common practice to start each day at
and end it at ?
9. In terms of AM and PM, what time would it be at 2005?
10. How long a time is there between the striking of bells during the work day onboard ships?
11. Using the Ship’s Bell Time, an number of bells mark an hour, and an number of
bells mark a half hour?
12. When are Bells rung aboard ship?
13. What are the exceptions to Question # 12?
14. Onboard ship, bell are not generally struck for time purposes between what two times?
15. What are the names of the different watches aboard ship, when do they start, and how many
hours are they?
16. If working during the first dog watch and you hear 3 bells, what time is it?
17. How many bells would be sounded at 1500 during the afternoon watch?
18. You are working the morning watch and you hear 7 bells, What time is it and how long before
your watch ends?
19. In the 16th Century, who established that the Earth’s Rotation makes the Sun seem to move?
20. How many degrees of arc around the earth does the Sun appear to move each hour of the
21. How long will it take the Earth to rotate 1°?
22. Time measured by the Sun is known as what?
23. What is the position of the Sun at Noon?
24. At the Equator, how long does it take the Earth to move one minute of arc and what is this
25. Average solar time, based on the Sun’s apparent journey around the Earth (360°) in exactly
24 hours is known as what?
26. The time at your location based on the mean position of the Sun — that is 1200, the mean Sun
is over your meridian, not the actual Sun is known as what?
27. The difference between apparent time and the mean time is known as what?
28. What does UTC stand for and what is another name?
29. What radioactive element is used as the standard for atomic clocks world-wide?
30. Time based on the relationship of the mean Sun to the prime meridian is known as what?
31. How many degrees of arc is each Time Zone?
32. A Letter and a negative or positive number for 1 to 12, east or west of the prime meridian is
known as what?
33. What affect does Daylight Savings Time have on navigation at sea?
34. What are the names of the 4 CONUS Time Zones from East to West and how are they identified?
35. Most information in navigational tables and naval communications uses what type of time?
36. Starting from the Prime Meridian, how are the standard time zones numbered?
37. What is the algebraic procedure to go from zone time (ZT) to Greenwich time (GMT),or to go
from GMT to ZT?
38. What would be the GMT if it was April 2 at 2000 in Pensacola, FL (ZD=+6)?
39. What is the time zone description at Greenwich?
40. What would be the zone time for Jacksonville, Florida if it was April 2 at 1600 GMT?
41. If a naval message originated in San Diego, CA at 2330 local time on April 10 2009, what
would the date-time group of that message be?