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

A cocked hat is the triangle formed when three bearing lines fail to meet at a single point, indicating errors in the observed bearings or timing.

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

The mnemonic 'Can Dead Men Vote Twice' gives: Compass + Deviation = Magnetic, Magnetic + Variation = True, so True = Compass + Deviation + Variation (applying correct signs).

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

A current setting 270°T directly opposes the vessel's 090°T course, reducing speed over ground to 9 knots without altering the course made good.

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

A running fix uses two bearings on the same object taken at different times; the first line of position is advanced to the time of the second bearing to produce a fix.

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

Leeway is the angular difference between a vessel's steered heading and its actual course made good, caused by the sideways force of wind on the hull and superstructure.

(DWO) Deck Watch Officer Practice Test

(DWO) Deck Watch Officer Practice Test

DWO Chart Work and Pilotage 2