CERTIFICATION EXAM QUESTIONS AND CORRECT
ANSWERS Q&A 2026 |INSTANT DOWNLOAD PDF
1. What is the primary purpose of hydrographic surveying?
A. Measuring soil fertility
B. Mapping underwater features
C. Studying weather patterns
D. Measuring air pressure
Rationale: Hydrographic surveying focuses on underwater
terrain and water bodies.
Correct Answer: B
2. Which instrument is commonly used to measure water
depth?
A. Barometer
B. Thermometer
C. Echo sounder
D. Hygrometer
Rationale: Echo sounders use sound waves to measure depth.
Correct Answer: C
3. What does bathymetry refer to?
,A. Study of rainfall
B. Measurement of land elevation
C. Measurement of underwater depths
D. Study of ocean currents only
Rationale: Bathymetry is the underwater equivalent of
topography.
Correct Answer: C
4. Which GPS system is most commonly used in modern
hydrographic surveys?
A. Optical GPS
B. Differential GPS (DGPS)
C. Analog GPS
D. Manual GPS
Rationale: DGPS improves positional accuracy.
Correct Answer: B
5. What is a sonar system used for?
A. Measuring salinity
B. Detecting underwater objects
C. Measuring wind speed
D. Recording temperature
Rationale: SONAR uses sound propagation underwater.
Correct Answer: B
,6. What is a chart datum?
A. Atmospheric pressure level
B. Reference level for depth measurements
C. Temperature baseline
D. GPS calibration value
Rationale: It is a reference for hydrographic depths.
Correct Answer: B
7. Which of the following affects sound speed in water?
A. Color of water
B. Salinity, temperature, pressure
C. Wind direction
D. Moon phase
Rationale: Physical properties affect sound velocity.
Correct Answer: B
8. What is a tide gauge used for?
A. Measuring wind speed
B. Recording sea level changes
C. Measuring rainfall
D. Measuring sediment load
Rationale: Tide gauges monitor sea level fluctuations.
Correct Answer: B
, 9. What is multibeam sonar used for?
A. Measuring river flow
B. Mapping large seafloor areas
C. Measuring air quality
D. Tracking fish migration only
Rationale: It creates wide swath bathymetric maps.
Correct Answer: B
10. Which coordinate system is commonly used in
hydrographic surveys?
A. Cartesian only
B. Geographic (Latitude/Longitude)
C. Polar only
D. Random grid system
Rationale: Latitude and longitude define positions globally.
Correct Answer: B
11. What is the primary purpose of echo sounding?
A. Measure air pressure
B. Measure water depth
C. Measure wind speed
D. Measure salinity
Rationale: Echo sounding uses sound reflection to determine
depth.
Correct Answer: B