USCG COXSWAIN EXAM QUESTIONS AND 100% VERIFIED
ANSWERS RECENTLY UPDATED
300 PRACTICE QUESTIONS AND ANSWERS
1. Q: What is a bearing? A: The horizontal direction or angle between a
reference direction (usually true north) and a line from the observer to an object.
2. Q: What is the difference between true bearing and magnetic bearing?
A: True bearing is measured from true north; magnetic bearing is measured
from magnetic north. The difference is the magnetic variation.
3. Q: How do you convert from magnetic to true bearing? A: Add easterly
variation or subtract westerly variation (remember: "East is least, West is best").
4. Q: What is compass deviation? A: The deflection of the magnetic compass
needle from magnetic north due to local magnetic influences aboard the vessel.
5. Q: What is the purpose of a compass rose on a chart? A: To show true and
magnetic directions and provide the magnetic variation for that area.
6. Q: What does GPS stand for? A: Global Positioning System.
7. Q: What is the accuracy of civilian GPS? A: Typically within 3-5 meters
under normal conditions.
8. Q: What is a waypoint? A: A specific geographical location defined by
latitude and longitude coordinates used for navigation.
9. Q: What is course over ground (COG)? A: The actual direction of travel
over the earth's surface.
10. Q: What is speed over ground (SOG)? A: The actual speed of the vessel
over the earth's surface.
11. Q: What is the difference between course and track? A: Course is the
intended direction; track is the actual path traveled.
,12. Q: What is set and drift in navigation? A: Set is the direction of current;
drift is the speed of current.
13. Q: What is dead reckoning? A: Determining position by advancing a
previous position based on course and speed.
14. Q: What is a fix in navigation? A: A position determined by two or more
intersecting lines of position.
15. Q: What is piloting? A: Navigation by reference to visible landmarks and
aids to navigation.
16. Q: What are the standard chart symbols for rocks? A: Asterisks (*) for
rocks that cover and uncover; dots for submerged rocks.
17. Q: What does a magenta circle on a chart indicate? A: The approximate
position of a GPS waypoint or electronic chart feature.
18. Q: What is the international date line? A: The 180° meridian where the
date changes by one day when crossing.
19. Q: What is latitude? A: Angular distance north or south of the equator,
measured in degrees, minutes, and seconds.
20. Q: What is longitude? A: Angular distance east or west of the Prime
Meridian, measured in degrees, minutes, and seconds.
21. Q: How many minutes of latitude equal one nautical mile? A: One
minute of latitude equals one nautical mile.
22. Q: What is the Prime Meridian? A: The 0° line of longitude passing
through Greenwich, England.
23. Q: What is a nautical mile? A: 6,076 feet or 1,852 meters; one minute of
latitude.
24. Q: What is a statute mile? A: 5,280 feet or 1,609 meters.
25. Q: How do you convert knots to MPH? A: Multiply knots by 1.15 to get
approximate MPH.
26. Q: What is the difference between chart datum and tidal datum? A:
Chart datum is the reference level for depths; tidal datum is the reference for
tide heights.
, 27. Q: What does MLLW stand for? A: Mean Lower Low Water - the chart
datum used on the West Coast.
28. Q: What does MLW stand for? A: Mean Low Water - the chart datum
used on the East Coast.
29. Q: What is the height of tide? A: The vertical distance between the water
surface and chart datum.
30. Q: What is range of tide? A: The difference in height between high and
low water.
31. Q: What is a spring tide? A: Tides with the greatest range, occurring
during new and full moon.
32. Q: What is a neap tide? A: Tides with the smallest range, occurring during
first and third quarter moon.
33. Q: What causes tides? A: Gravitational forces of the moon and sun acting
on Earth's waters.
34. Q: What is tidal current? A: The horizontal movement of water caused by
tidal forces.
35. Q: What is slack water? A: The period of little or no current between flood
and ebb tides.
36. Q: What is flood current? A: Tidal current flowing toward shore or
upstream.
37. Q: What is ebb current? A: Tidal current flowing away from shore or
downstream.
38. Q: What publication provides tide predictions? A: Tide Tables published
by NOAA.
39. Q: What publication provides tidal current predictions? A: Tidal
Current Tables published by NOAA.
40. Q: What is a subordinate tide station? A: A location where tides are
predicted using time and height differences from a reference station.
41. Q: What is the rule of twelfths for tides? A: A method to estimate tide
height at any time: 1/12, 2/12, 3/12, 3/12, 2/12, 1/12 of the range in successive
hours.
ANSWERS RECENTLY UPDATED
300 PRACTICE QUESTIONS AND ANSWERS
1. Q: What is a bearing? A: The horizontal direction or angle between a
reference direction (usually true north) and a line from the observer to an object.
2. Q: What is the difference between true bearing and magnetic bearing?
A: True bearing is measured from true north; magnetic bearing is measured
from magnetic north. The difference is the magnetic variation.
3. Q: How do you convert from magnetic to true bearing? A: Add easterly
variation or subtract westerly variation (remember: "East is least, West is best").
4. Q: What is compass deviation? A: The deflection of the magnetic compass
needle from magnetic north due to local magnetic influences aboard the vessel.
5. Q: What is the purpose of a compass rose on a chart? A: To show true and
magnetic directions and provide the magnetic variation for that area.
6. Q: What does GPS stand for? A: Global Positioning System.
7. Q: What is the accuracy of civilian GPS? A: Typically within 3-5 meters
under normal conditions.
8. Q: What is a waypoint? A: A specific geographical location defined by
latitude and longitude coordinates used for navigation.
9. Q: What is course over ground (COG)? A: The actual direction of travel
over the earth's surface.
10. Q: What is speed over ground (SOG)? A: The actual speed of the vessel
over the earth's surface.
11. Q: What is the difference between course and track? A: Course is the
intended direction; track is the actual path traveled.
,12. Q: What is set and drift in navigation? A: Set is the direction of current;
drift is the speed of current.
13. Q: What is dead reckoning? A: Determining position by advancing a
previous position based on course and speed.
14. Q: What is a fix in navigation? A: A position determined by two or more
intersecting lines of position.
15. Q: What is piloting? A: Navigation by reference to visible landmarks and
aids to navigation.
16. Q: What are the standard chart symbols for rocks? A: Asterisks (*) for
rocks that cover and uncover; dots for submerged rocks.
17. Q: What does a magenta circle on a chart indicate? A: The approximate
position of a GPS waypoint or electronic chart feature.
18. Q: What is the international date line? A: The 180° meridian where the
date changes by one day when crossing.
19. Q: What is latitude? A: Angular distance north or south of the equator,
measured in degrees, minutes, and seconds.
20. Q: What is longitude? A: Angular distance east or west of the Prime
Meridian, measured in degrees, minutes, and seconds.
21. Q: How many minutes of latitude equal one nautical mile? A: One
minute of latitude equals one nautical mile.
22. Q: What is the Prime Meridian? A: The 0° line of longitude passing
through Greenwich, England.
23. Q: What is a nautical mile? A: 6,076 feet or 1,852 meters; one minute of
latitude.
24. Q: What is a statute mile? A: 5,280 feet or 1,609 meters.
25. Q: How do you convert knots to MPH? A: Multiply knots by 1.15 to get
approximate MPH.
26. Q: What is the difference between chart datum and tidal datum? A:
Chart datum is the reference level for depths; tidal datum is the reference for
tide heights.
, 27. Q: What does MLLW stand for? A: Mean Lower Low Water - the chart
datum used on the West Coast.
28. Q: What does MLW stand for? A: Mean Low Water - the chart datum
used on the East Coast.
29. Q: What is the height of tide? A: The vertical distance between the water
surface and chart datum.
30. Q: What is range of tide? A: The difference in height between high and
low water.
31. Q: What is a spring tide? A: Tides with the greatest range, occurring
during new and full moon.
32. Q: What is a neap tide? A: Tides with the smallest range, occurring during
first and third quarter moon.
33. Q: What causes tides? A: Gravitational forces of the moon and sun acting
on Earth's waters.
34. Q: What is tidal current? A: The horizontal movement of water caused by
tidal forces.
35. Q: What is slack water? A: The period of little or no current between flood
and ebb tides.
36. Q: What is flood current? A: Tidal current flowing toward shore or
upstream.
37. Q: What is ebb current? A: Tidal current flowing away from shore or
downstream.
38. Q: What publication provides tide predictions? A: Tide Tables published
by NOAA.
39. Q: What publication provides tidal current predictions? A: Tidal
Current Tables published by NOAA.
40. Q: What is a subordinate tide station? A: A location where tides are
predicted using time and height differences from a reference station.
41. Q: What is the rule of twelfths for tides? A: A method to estimate tide
height at any time: 1/12, 2/12, 3/12, 3/12, 2/12, 1/12 of the range in successive
hours.
