Rules of the Road · Light Definitions & Visibility
A 'masthead light' under the COLREGS shows over an arc of how many degrees?
- A112.5 degrees
- B135 degrees
- C225 degrees✓ Correct
- D360 degrees
Explanation
Rule 21(a) defines a masthead light as showing an unbroken arc of 225 degrees, from dead ahead to 22.5 degrees abaft the beam on each side. This distinguishes it from an all-round light which covers 360 degrees.
Authority: 72 COLREGS Rule 21(a)
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