23
Power-driven Vessels Underway
Power-driven vessels underway shall exhibit masthead light(s), sidelights, and sternlight. Vessels 50m+ require two masthead lights.
Rule 23 specifies lights for power-driven vessels underway.
a
A power-driven vessel underway shall exhibit:
- 1A masthead light forward
- 2A second masthead light abaft of and higher than the forward one — except that a vessel of less than 50 metres in length shall not be obliged to exhibit such light but may do so
- 3Sidelights — red (port) and green (starboard)
- 4A sternlight
b
An air-cushion vessel when operating in the non-displacement mode shall, in addition, exhibit an all-round flashing yellow light.
Key Takeaways
1
Vessels 50m+ must show two masthead lights
2
All power-driven vessels show sidelights and sternlight
3
Second masthead light must be higher than the forward one
4
Hovercraft show additional flashing yellow light
Common Mistakes
Small vessels displaying two masthead lights unnecessarily
Confusing the vertical positioning of forward and after masthead lights
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