DWO Chart Work and Pilotage

Question 1

What datum is used for soundings on US nautical charts?

Accepted Answer

Mean Lower Low Water (MLLW)

Answer

Mean High Water

Answer

Mean Sea Level

Answer

Mean Low Water

Question 2

What does blue tinting on a nautical chart typically indicate?

Accepted Answer

Shallow water less than the specified depth contour

Answer

Deep water exceeding 200 meters

Answer

Restricted anchorage areas

Answer

Areas of strong tidal current

Question 3

What does the abbreviation 'PA' printed next to a chart symbol mean?

Accepted Answer

Position Approximate

Answer

Protected Area

Answer

Port Authority

Answer

Pilotage Area

Question 4

On a nautical chart, a magenta circle with a dot in the center represents what type of navigational aid?

Accepted Answer

A fixed light structure such as a lighthouse

Answer

A danger rock awash

Answer

A light buoy

Answer

A radiobeacon

Question 5

Which statement correctly describes a large-scale nautical chart?

Accepted Answer

It shows a small geographic area with greater detail

Answer

It shows a large geographic area with minimal detail

Answer

It has a smaller representative fraction than a small-scale chart

Answer

It is used primarily for ocean passage planning

Question 6

What does the abbreviation 'ED' following a sounding on a nautical chart indicate?

Accepted Answer

Existence Doubtful

Answer

Extra Deep

Answer

Electronically Determined

Answer

Estimated Depth

Question 7

What is the purpose of a 'cautionary note' printed on a nautical chart?

Accepted Answer

To warn mariners of specific navigational hazards or restrictions

Answer

To indicate areas closed to commercial shipping

Answer

To mark areas requiring special entry permits

Answer

To identify areas with unreliable tidal data