21 - Lights and Shapes Definitions

Question 1

Masthead light

International

Answer 1

• White light over the fore and aft centerline of the vessel
• Unbroken light over an arc of the horizon of 225°
• Fixed as to show the light from right ahead of 22.5° abaft the beam on either side of the vessel

Question 2

Masthead light

Inland

Answer 2

Same as International EXCEPT
- If a vessel is < 12m the light shall be placed as practicable to the fore and aft centerline of the vessel

Question 3

Sidelights

International

Answer 3

• Green light on STBD, Red light on PORT side
• Unbroken light over an arc of the horizon of 112.5°
• Fixed to show the light from right ahead to 22.5°
• In a vessel < 20m the sidelights may be combined in one lantern carried on the fore and aft centerline

Question 4

Sidelights

Inland

Answer 4

Same as International EXCEPT
- On a vessel < 12m the combined sidelights shall be placed as nearly as practicable to the fore and aft centerline of the vessel

Question 5

Sternlight

Inland & International

Answer 5

• White light placed as practicable at the stern
• Unbroken light over an arc of the horizon of 135°
• Fixed to show the light 67.5° from right aft on each side of the vessel

Question 6

Towing Light

Inland & International

Answer 6

A yellow light with the same characteristics as a sternlight

Question 7

All-round light

Inland & International

Answer 7

A light showing an unbroken light over an arc of the horizon of 360°

Question 8

Flashing Light

Inland & International

Answer 8

A light flashing at regular intervals at a frequency of 120 flashes/minute

Question 9

Special Flashing Light

Inland only

Answer 9

• Yellow light
• Flashes at regular intervals at a frequency of 50-70 FPM
• Shows an unbroken light over an arc of the horizon of not less than 180° nor more than 225° abaft the beam on either side of the vessel