ASA 105 Exam v1 Practice Questions and Answers
Compass & Navigation
1. Inner degree circle on compass rose → Magnetic
2. Outer degree circle on compass rose → Geographic (True)
3. Difference between geographic and magnetic north → Variation
4. Most basic navigation method (ignores current/leeway) → Dead Reckoning (DR)
5. Two factors considered in DR → Distance, Direction (magnetic)
6. Correct DR plot label (5kts, 10nm, 090°M) → 5kts / 10nm / 090°M
Buoys, Harbors & Rules
7. Rule for piloting into US harbor → Red, Right, Return
8. Returning south/west along Atlantic & Gulf coasts → Intracoastal Waterway
(ICW)
9. Three elements in buoy/marker system → Shape, Color, Number
10. Preferred side of channel when entering harbor → Starboard (red buoys to
starboard)
Depth & Measurement
11. At less than 11 fathoms, notation used → Fathoms plus feet
12. Depth readings vary depending on → Transducer location
13. Chart soundings reference → Mean Lower Low Water (MLLW)
14. Depth contour lines show → Changes in seabed elevation
Charts & Plotting
15. General chart (small scale 1:600,000) → General Chart
16. Large-scale chart with detail of harbor → Harbor Chart
17. Chart datum definition → Reference level for depths/heights
18. Latitude lines measure → North–South position
19. Longitude lines measure → East–West position
, Bearings & Variation
20. Bearing measured clockwise from true north → True Bearing
21. Bearing measured clockwise from magnetic north → Magnetic Bearing
22. Compass error caused by ship’s metal → Deviation
23. Formula to convert True → Magnetic → Compass → “True – Variation =
Magnetic; Magnetic – Deviation = Compass”
Practical Seamanship
24. Fix obtained by crossing two bearings → Cross Bearing Fix
25. Fix obtained by advancing DR with estimated set/drift → Estimated Position (EP)
Tides & Currents
26. Reference level for charted depths → Mean Lower Low Water (MLLW)
27. Vertical rise/fall of water due to moon/sun → Tide
28. Horizontal movement of water due to tide → Tidal Current
29. Tide prediction tables are based on → Harmonic Analysis
30. Strongest tidal currents occur at → Mid-tide (between high and low)
Piloting & Position Fixing
31. Fix obtained by three bearings → Three-Point Fix
32. Fix obtained by advancing DR with set/drift → Estimated Position (EP)
33. Fix obtained by GPS → Electronic Fix
34. Fix obtained by crossing LOPs (lines of position) → Fix
35. Best fix accuracy comes from → Bearings intersecting at wide angles
Bearings & Headings
36. Compass error caused by ship’s magnetic field → Deviation
37. Formula: True → Magnetic → Compass → True – Variation = Magnetic;
Magnetic – Deviation = Compass
38. Bearing measured clockwise from true north → True Bearing
Compass & Navigation
1. Inner degree circle on compass rose → Magnetic
2. Outer degree circle on compass rose → Geographic (True)
3. Difference between geographic and magnetic north → Variation
4. Most basic navigation method (ignores current/leeway) → Dead Reckoning (DR)
5. Two factors considered in DR → Distance, Direction (magnetic)
6. Correct DR plot label (5kts, 10nm, 090°M) → 5kts / 10nm / 090°M
Buoys, Harbors & Rules
7. Rule for piloting into US harbor → Red, Right, Return
8. Returning south/west along Atlantic & Gulf coasts → Intracoastal Waterway
(ICW)
9. Three elements in buoy/marker system → Shape, Color, Number
10. Preferred side of channel when entering harbor → Starboard (red buoys to
starboard)
Depth & Measurement
11. At less than 11 fathoms, notation used → Fathoms plus feet
12. Depth readings vary depending on → Transducer location
13. Chart soundings reference → Mean Lower Low Water (MLLW)
14. Depth contour lines show → Changes in seabed elevation
Charts & Plotting
15. General chart (small scale 1:600,000) → General Chart
16. Large-scale chart with detail of harbor → Harbor Chart
17. Chart datum definition → Reference level for depths/heights
18. Latitude lines measure → North–South position
19. Longitude lines measure → East–West position
, Bearings & Variation
20. Bearing measured clockwise from true north → True Bearing
21. Bearing measured clockwise from magnetic north → Magnetic Bearing
22. Compass error caused by ship’s metal → Deviation
23. Formula to convert True → Magnetic → Compass → “True – Variation =
Magnetic; Magnetic – Deviation = Compass”
Practical Seamanship
24. Fix obtained by crossing two bearings → Cross Bearing Fix
25. Fix obtained by advancing DR with estimated set/drift → Estimated Position (EP)
Tides & Currents
26. Reference level for charted depths → Mean Lower Low Water (MLLW)
27. Vertical rise/fall of water due to moon/sun → Tide
28. Horizontal movement of water due to tide → Tidal Current
29. Tide prediction tables are based on → Harmonic Analysis
30. Strongest tidal currents occur at → Mid-tide (between high and low)
Piloting & Position Fixing
31. Fix obtained by three bearings → Three-Point Fix
32. Fix obtained by advancing DR with set/drift → Estimated Position (EP)
33. Fix obtained by GPS → Electronic Fix
34. Fix obtained by crossing LOPs (lines of position) → Fix
35. Best fix accuracy comes from → Bearings intersecting at wide angles
Bearings & Headings
36. Compass error caused by ship’s magnetic field → Deviation
37. Formula: True → Magnetic → Compass → True – Variation = Magnetic;
Magnetic – Deviation = Compass
38. Bearing measured clockwise from true north → True Bearing
