DWO Chart Work and Pilotage 2

Question 1

When taking a three-bearing fix, what does a 'cocked hat' indicate?

Accepted Answer

The three lines of position do not converge at a single point due to accumulated errors

Answer

The vessel is in dangerous shoal water

Answer

Excessive compass deviation is present

Answer

The vessel's speed changed during the fix

Question 2

Using the mnemonic 'Can Dead Men Vote Twice,' what is the correct formula to convert compass bearing to true bearing?

Accepted Answer

True = Compass + Deviation + Variation

Answer

True = Compass - Deviation - Variation

Answer

True = Compass + Variation - Deviation

Answer

True = Compass × (Deviation + Variation)

Question 3

A vessel steers 090°T at 12 knots. A current sets 270°T at 3 knots. What is the vessel's speed over ground?

Accepted Answer

9 knots

Answer

15 knots

Answer

12 knots

Answer

6 knots

Question 4

What is the purpose of a running fix?

Accepted Answer

To find position using a single object's bearing taken at two different times

Answer

To determine position using radar bearings only

Answer

To verify a GPS fix against a visual bearing

Answer

To calculate ETA at the next waypoint

Question 5

What is 'leeway' in coastal navigation?

Accepted Answer

The angular difference between a vessel's heading and course made good caused by wind

Answer

The difference between magnetic and compass course

Answer

The rate at which a vessel drifts with a tidal current

Answer

The distance a vessel travels sideways during a turn

Question 6

What is a 'danger bearing'?

Accepted Answer

A pre-plotted bearing limit that, if crossed, places the vessel in danger

Answer

A compass bearing affected by a local magnetic anomaly

Answer

The bearing of a hazard measured from the vessel's charted position

Answer

A bearing taken on a light during restricted visibility

Question 7

When must a vessel's estimated position (EP) be used instead of a fix?

Accepted Answer

When only dead reckoning data is available and no external references can be obtained

Answer

When two or more lines of position are available

Answer

When the GPS and radar agree on position

Answer

When speed has been constant for over one hour