On national holidays and on other special occasions US Navy ships
often "dress ship" using International Code signal flags.
Typically the ship is dressed on these occasions only while at anchor or moored, and then from 0800 until evening colors.
"Dress Ship" flags are typically flown underway for the entire duration of a vessel's maiden and final voyages'
or when participating in an official marine parade.
the fine print...
Protocol details for displaying flags, pennants, etc aboard U.S. Naval and U.S. Coast Guard vessels are found in the following document:
NAVAL TELECOMMUNICATIONS PROCEDURES
FLAGS, PENNANTS & CUSTOMS
NTP 13 (B) Aug 1986
Here are some pertinent parts:
Section 602. DISPLAY OF THE U.S. NATIONAL ENSIGN DURING DRESS
AND FULL-DRESS SHIP
On occasions of dress and full-dress ship, the largest national ensign in the ships allowance shall be displayed from the flagstaff and.... the Union Jack is be displayed at the jack (bow) staff.
Section 701. PURPOSE
The purpose of dress and full-dress ship is to recognize U.S. and, upon official invitation, foreign national anniversaries or solemnities. Display of the U.S. and foreign national ensigns at the mastheads during periods of dress and full-dress ship is explained in Chapter 6.
Section 702. APPLICABILITY
Ships not underway shall dress or full-dress from 0800 until sunset. Ships underway do not dress or full-dress.
Section 704. RAINBOW COLORS
On occasions of full-dress ship a rainbow of signal flags and pennants, arranged in the order prescribed herein, shall be displayed. The rainbow shall reach from the foot of the jack staff to the mastheads and thence to the foot of the flagstaff.
Section 705. SEQUENCE OF SIGNAL FLAGS AND PENNANTS
The sequence of signal flags and pennants for the rainbow display shall be as follows:
(1) Flags shall be displayed from stem beginning with (1) Flag 3, then (2) Flag 4, then (3) Pennant 1, etc,
(2) If one set of flags does not complete the rainbow, repeat the sequence starting with Flag 3, Flag 4, etc.
(3) All flags and pennants in the allied flag bag are used except "Screen", "Subdiv", and "Group".
Special Flags and Pennants
Constitution at Boston Navy Yard
||U.S.C.G.C. Eagle at Boston
Both of America's Tall Ships in Full Dress while
in Boston, Massachusetts (dates uncertain).
On the left is the U.S.S. Constitution a.k.a. "Old Ironsides". She is 304' long and was built in 1794 -1797. The Constitution is the world's oldest commissioned naval vessel afloat. She is scheduled to commence a 3-year overhaul in March 2015.
Above is the U.S. Coast Guard Cutter Eagle (WIX-327), 295' long. She is a training ship for the U.S. Coast Guard and is the only active commissioned tallship in the U.S. military. She is a war prize, originally the Horst Wessel, a training vessel for the German Navy.
Sorting flags on Coast Guard's tallship Eagle
Above, on board the U.S. Coast Guard's tallship USCGC Eagle (circa 2000), Webmaster Art Tilley ET2 (USCGR)
helps three Coast Guard Academy cadets sort through flags and pennants in preparation for a Dress Ship event (New York City I think!)
So.... what is the flag/pennant that is being discussed by the guys, and where does it go in the sequence?