Shifting Colors

When a ship is anchored or moored between 8.00 a.m and sunset, she fly her ensign at the flagstaff and the jack at the jack staff. When underway, the ensign is flown at the gaff (the diagonal spar projecting aft from the mast) and the jack is not flown at all. The process of changing from one display to the other is known as shifting colors. 

• The ensign at the flagstaff and the jack at the jackstaff are hauled down smartly (rapidly).

• The steaming ensign is run up smartly to the gaff.

• Any flags or pennants that are displayed only when not under way, such as award pennants or  the personal flag or pennant of an officer who is not aboard, are hauled down smartly.

• The call sign is broken at the signal yard.

As the ship prepares to get under way, sailors are positioned at the bow, fantail, and bottom of the halyards running to the gaff and the signal yards. The "steaming" ensign is attached--or "bent on"--to its halyard in preparation for hoisting. The ship's call sign and any other prescribed signal flags are run up, packed to be "broken" at the right moment. At the instant that the last mooring line leaves the pier or buoy, or the moment that the anchor is aweigh, the boatswain's mate of the watch blows a long blast on his whistle and passes the word, "Underway--shift colors." Immediately and simultaneously:

A ship mooring or coming to anchor goes through the same process in reverse, with the boatswain's mate giving the word "Moored--shift colors" when the first mooring line is made fast or the anchor is let go. In either case, the desired effect is one set of flags vanishing and another flashing out at precisely the same time.