CH Navigation & Nautical Chart Production 2

Question 1

In chart production, the process of converting raw survey soundings to chart datum depth values requires:

Accepted Answer

Subtracting the water level (tide) at the time of measurement from the measured depth

Answer

Tide-corrected soundings are obtained by subtracting the observed water level above chart datum at the time of sounding from the measured depth below the water surface.

Question 2

What NOAA publication defines the specifications and standards for nautical chart compilation and hydrographic surveys?

Accepted Answer

NOAA Hydrographic Surveys Specifications and Deliverables (HSSD)

Answer

NOAA's Hydrographic Surveys Specifications and Deliverables (HSSD) document defines all technical requirements for surveys that will be used in nautical chart production.

Question 3

Electronic Navigational Charts (ENCs) used in ECDIS systems conform to which international standard?

Accepted Answer

IHO S-57 / S-100

Answer

ENCs are encoded in IHO S-57 format (with S-100 as the next-generation framework), which defines the data model, feature catalog, and exchange format for official electronic charts.

Question 4

A 'scale of 1:80,000' on a nautical chart means that one unit on the chart represents:

Accepted Answer

80,000 units of the same measurement in reality

Answer

A representative fraction of 1:80,000 means one unit measured on the chart (e.g., 1 cm) corresponds to 80,000 of the same units in the real world (80,000 cm = 800 m).

Question 5

On a nautical chart, what does a magenta circle with a flashing light characteristic 'Fl(2) 10s 15m 12M' describe?

Accepted Answer

A light structure with group flashes of 2, 10-second period, 15 meters elevation, 12 nautical mile nominal range

Answer

The notation means: group flashing with 2 flashes per period, period of 10 seconds, light elevation 15 meters above MHWS, nominal range 12 nautical miles.

(CH) Certified Hydrographer Practice Test

(CH) Certified Hydrographer Practice Test

CH Navigation & Nautical Chart Production 2