Sailing Vessel Lights. It does not display a forward facing masthead light as that would mean it was being propelled by machinery. Sailing vessels less than 20 metres in length may use a combination mast top tri-color light in place of the standard red and green side lights and white stern light.
Knowing that the bow lights go 225 degrees abaft the beam on both sides or 1125 degrees on each side and the stern light faces 225 degrees aft for a total of 360 degrees of visibility you can tell a lot about where a boat is heading and who has the right of way. When sailing the vessel has to display red and green side lights and a white stern light. The lights for sailing vessels are very similar to those of power driven vessels plus a couple of extra options.
Rule 25a Sailboats Under Sail Only.
A sailing vessel underway may in addition to the lights exhibit at or near the top of the mast where they can best be seen two all-round lights in a vertical line the upper being red and the lower green but these lights shall not be exhibited in conjunction with the combined lantern. In accordance with Rule 25 a Sailings vessels underway and vessels under oars a sailing vessel underway shall exhibit. Sailing vessels less than 20 metres in length may use a combination mast top tri-color light in place of the standard red and green side lights and white stern light. A sailing vessel may exhibit at or near the top of the mast two all-round lights in a vertical line.
