Originally Posted by Bestathook
Viewed from the height of an elevated bridge above, in limited visibility, a light at masthead height appears the same as a deck level light on a vessel much farther away. It looks like a low light that is much farther away, when in fact it is dangerously close. By the time the lookout or helmsman can see the boat hull
and mast, the vessels are dangerously close.
What he said....
The other risk inshore is that the tricolour at the masthead will be just above the shoreline as seen from a ship's bridge. Then it blends in very nicely with the shore lights. Also picture yourself on a fast motorboat overtaking a yacht using his tricolour on a clear starlight night or using a masthead mounted anchor
light in the same situation.
Not going to agree regarding showing both deck level and masthead lights though.
The red over green at the masthead was introduced for use by larg(ish) sailing ships which could be mistaken for power driven vessels ( speed and big fat radar
return) that had popped the bulb(s) in their steaming light(s).
Re popping bulbs - on my last day job we took to leaving the nav lights on 24 hours a day as we used to blow bulbs very frequently at switch on... dunno why.