BOTH INTERNATIONAL & INLAND A white masthead...

Question 1 / 2707066636eeb28f7522a1c51be3c

Question 1 of 2707066636eeb28f7522a1c51be3c

BOTH INTERNATIONAL & INLAND A white masthead light shows through an arc of how many degrees?

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Question 1 of 27070

Q

BOTH INTERNATIONAL & INLAND A white masthead light shows through an arc of how many degrees?

🔍 Key Concepts

• Masthead light definition and where it is placed on a power-driven vessel • Required arc of visibility for masthead lights under the Navigation Rules (COLREGS, Rule 21) • How masthead light coverage compares to side lights and stern lights

💭 Think About

• Think about whether a masthead light is meant to be seen from directly ahead only, or also partly on the sides of a vessel. • Compare the coverage of the masthead light to the stern light: together, should they cover the full circle around the vessel? • Ask yourself: if the masthead light covers a certain number of degrees on one side of the bow, what would be the total angle it must cover centered on the vessel’s heading?

✅ Before You Answer

• Look up the exact arc of visibility for a masthead light in Rule 21 – Definitions of the Navigation Rules. • Verify how many degrees are covered by the stern light and confirm that masthead + stern = 360° around the vessel. • Confirm that the masthead light is visible from right ahead to a specified number of degrees abaft the beam on each side.

Question 1 of 27070

Q

BOTH INTERNATIONAL & INLAND A white masthead light shows through an arc of how many degrees?

A

90°

B

112.5°

C

225°

D

360°

Question 1 / 2707066636eeb28f7522a1c51be3c

Question 1 of 2707066636eeb28f7522a1c51be3c

BOTH INTERNATIONAL & INLAND A white masthead light shows through an arc of how many degrees?

Back

Question 1 of 27070

Q

BOTH INTERNATIONAL & INLAND A white masthead light shows through an arc of how many degrees?

🔍 Key Concepts

• Masthead light definition and where it is placed on a power-driven vessel • Required arc of visibility for masthead lights under the Navigation Rules (COLREGS, Rule 21) • How masthead light coverage compares to side lights and stern lights

💭 Think About

• Think about whether a masthead light is meant to be seen from directly ahead only, or also partly on the sides of a vessel. • Compare the coverage of the masthead light to the stern light: together, should they cover the full circle around the vessel? • Ask yourself: if the masthead light covers a certain number of degrees on one side of the bow, what would be the total angle it must cover centered on the vessel’s heading?

✅ Before You Answer

• Look up the exact arc of visibility for a masthead light in Rule 21 – Definitions of the Navigation Rules. • Verify how many degrees are covered by the stern light and confirm that masthead + stern = 360° around the vessel. • Confirm that the masthead light is visible from right ahead to a specified number of degrees abaft the beam on each side.