DWO Navigation Rules 3

Question 1

Which factor does NOT determine whether a vessel is 'underway' under the Navigation Rules?

Accepted Answer

Moving through the water

Answer

Rule 3 defines 'underway' as not at anchor, not made fast to shore, and not aground — actual movement through the water is not required.

Question 2

What is the required arc of visibility for a vessel's masthead light?

Accepted Answer

225 degrees

Answer

Rule 21 specifies that a masthead light shows an unbroken white light over an arc of 225 degrees.

Question 3

In restricted visibility, a power-driven vessel making way through the water shall sound:

Accepted Answer

One prolonged blast at intervals of not more than 1 minute

Answer

Rule 35(a) requires a power-driven vessel making way to sound one prolonged blast at intervals of not more than 2 minutes.

Question 4

A vessel constrained by her draft shall exhibit which lights at night?

Accepted Answer

Three all-round red lights in a vertical line

Answer

Rule 28 requires a vessel constrained by her draft to show three all-round red lights in a vertical line.

Question 5

Under Rule 10, which vessel shall not impede the safe passage of a vessel following a traffic separation scheme?

Accepted Answer

A vessel crossing a traffic lane

Answer

Rule 10(c) states that a vessel crossing traffic lanes shall not impede the passage of vessels following those lanes.

(DWO) Deck Watch Officer Practice Test