Her work deck was illuminated with two strong white lights, and on her mast she was showing RED over RED. I did not see any running lights, that is, no sidelight, masthead light, or sternlight. As best as I can interpret, the signal was Vessel Not Under Command. This is based on the following conditions being applicable:
--inland waters, that is, the Great Lakes;
--the vessel was not underway, thus none of the usual running lights; and
--the vessel was unable to maneuver.
The nemonic for remembering this is Red over Red: the Captain is dead.
The definition of "Vessel not under command" means "a vessel which through some exceptional circumstance is unable to maneuver as required by these Rules and is therefore unable to keep out of the way of another vessel." But this usually implies some sort of emergency, like an engine failure.
I was expecting to see the signal for Vessel Restricted In Its Ability To Maneuver, which would be Red-over-White-over-Red. The nemonic for that is Red-White-Red, doing the work I dread. RULE 3 of the Navigation Rules says:
"The term vessel restricted in her ability to maneuver means a vessel which, from the nature of her work, is restricted in her ability to maneuver as required by these Rules and is therefore unable to keep out of the way of another vessel. The term vessels restricted in their ability to maneuver include, but are not limited to...A vessel engaged in laying, servicing, or picking up a navigation mark...."
This interpretation is also suggested in the Coast Guard pamphlet on navigation lights: "Vessel Restricted In Its Ability To Maneuver – A vessel unable to keep out of the way of other vessels because the nature of its work is hindering its ability to maneuver (buoy tender picking up a buoy, vessel transferring persons, provisions or cargo while underway, etc.)"
See https://www.uscg.mil/hq/cgcvc/cvc3/refe ... erence.pdf
I was looking at the USCGC MACKINAW with rather excellent Steiner binoculars, so I don't think I missed that white light between the two red lights on her mast. Did the Officer On Watch have the wrong setting on the navigation lamp switch?
Or was there some other snafu that caused the Not Under Command signal to be shown?
Or was there a burned out white light on the mast?
ASIDE: this is another sign of the end of the boating season: when the Coast Guard starts pulling out the regular buoys and changing them to winter versions to better survive the ice.