Subject: Red over green mast lights for sailboat
From: "PeteAlbright"

On ships and tugs ("ocean going tug/barge"), the port, starboard, stern,
masthead, and range lights are redundant, with two lights in a vertical
assembly. Both lights have the wiring and filement monitored, and if the
primary light fails, the spare can be switched on.

On smaller masts, 6" to10" pipe, the "upper red", "middle white", and "lower
red" NUC lights are usually sigle, and mounted off the mast to the side.
Anchor lights are also mounted off the side if there is not room on top.
Where the mast is large, mounting two lights is theusual method.

What you describe above, is RAM, not NUC.
On ships, you will frequently find the anchor lights mounted on seperate
"poles" (sometimes portable) where the light will be at the top of the pole
.....normally a single light. BG try picking out the anchor lights on a ship,
nowadays ..... where they also use all decklights, the anchor lights tend to
just blend in with the others.

Most of the ("ocean going tug/barge") barge lights are powered from local
batteries with solar panels, and have six lamps with automatic lamp
changers.

Interesting .... never seen one with any kind of lamp changer.

One light that is not in the rules, is a small directional blue
light, facing aft at the bow (usually behind the range light). The tug pilot
uses this light to locate the boy of the barge at night.

Called a "steering light", it's frequently found on most ships, in a centerline
position as far forward as possible.
BTW, it seems nowadays, that most have stopped referring to Masthead and Range,
just using Masthead. The Range light was always the after of the two lights,
when it's usage was common.

Shen