Power-driven vessel underway

A power-driven vessel underway shall exhibit:

• a masthead light forward;
• a 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;
• sidelights;
• a sternlight.

Power driven vessel underway, longer than 50 m
Abeam, port side	Ahead	Astern
Power driven vessel underway, shorter than 50 m
Abeam, port side	Ahead	Astern