A Discovery Channel episode involving the dive of a remotely controlled submersible revealed that the superstructure of the R.M.S Lusitania had not only been painted to resemble its armed merchant sister ship, but also that the name of the ship on the hull had been painted-over with the same color as the hull.  This is how the German U-Boat commander was suckered into firing on the Lusitania, even though the fleet was commanded not to, knowing that it would be the excuse Churchill and FDR wanted to encourge Americans to demand entry into the war against Germany.

The video was shown on TV May 2009 (I saw it), and published on the Web:
Treasure Quest: Lusitania Revealed (Full Episode) : Video ...
Added: May 19, 2009. Views: 712 Views Runtime: 43:11. 
dsc.discovery.com/videos/treasure-quest-lusitania-revealed-full-episode.html -  It was removed before 6/21/09 and can no longer be found.
A version of it will allegedly be shown on Discovery Channel Sunday, June 14 2009, 7:00 AM (in 17 hours, 16 minutes), Treasure Quest: Lusitania Revealed

British steamship of the Cunard Line, torpedoed without warning during World War I by a German submarine on May 7, 1915, off the southern coast of Ireland. The ship sank in less than 20 minutes with the loss of 1198 persons, including 128 Americans. The Germans asserted that the ship was carrying arms for the Allies (which later research proved to be true) and that Americans had been warned against taking passage on British vessels in a notice that had appeared in morning newspapers on the day the ship sailed from New York City.

Popular feeling against the Germans rose to a high pitch in the U.S. because of the Lusitania disaster, and strong sentiment developed for declaring war on Germany. President Woodrow Wilson chose a diplomatic course, however, and sent the German foreign ministry three successive notes, demanding that Germany disavow the sinking and make reparations. Germany refused to accept responsibility for the tragedy but did agree to make reparations and to sink no more passenger liners without warning.

An article from Funk & Wagnalls® New Encyclopedia. © 2006 World Almanac Education Group.

Secretary of State William Jennings Bryan resigned rather than risk war, while critics such as Theodore Roosevelt denounced Wilson for not being tougher.

1913 March 26 - False Flag 4 preparation: By arming merchant ships and ording them to ram U-boats, Britain forced Geramany to stop allowing vessels to abandon ship, and sink them without warning. In the diplomatic wrangling over the German submarine campaign in 1915- 1916, the United States Government persistently failed to acknowledge the validity of the German point that it was not reasonable to expect a submarine to endanger herself by giving warning to a merchantman that was likely to be armed and under orders to ram any U-boat encountered.

1915 May 7 - False Flag 4: A submarine of the German Imperial Navy sinks the Royal Mail Ship (R.M.S.) Lusitania, killing 124 U.S. citizens, and motivating the hitherto isolationist Americans to war, despite the fact that its passengers were warned in U.S. newspaper ads bought by Germany not to board the ship. The American and British manifests of this "armed merchant cruiser" (Lloyd's Registry) were falsified, claiming that it had no armaments, when in fact it was carrying tons of munitions.  On 2/28/009, a History Channel ocean treasure hunter episode revealed the stacks of the Lusitania were repainted to match her sister ship, the Mauretania an armed merchant vessel, and the white letters on the hull spelling "Lusitania" were painted black to match the hull.  The Germans bought ads warning the passengers not to sail on the Lusitania, because the Germans knew it was caring ammunition bound for England, and threatened to sink it.  What puzzled historians is the Germans, knowing that the sinking of the Lusitania would likely bring the U.S. into the war against them, still sank the ship.  Now we know.  The German submarine captain mistook the Lusitania for the Mauretania as intended by President Wilson to motivate Americans to war.

1917 June 4 - False Flag 4 result: Congress declares war on Germany "Whereas the Imperial German Government have committed repeated acts of war against the ... United States of American ... a state of war exists between the United States and the Imperial German government." The antagonists were prepared to renegotiate boundaries as they had done to end so many of their past European wars, but U.S. entry into the war against Germany extended WW I and its devastation, and resulted in the Versailles Treaty, which economically suffocated Germany, and paved the way for Hitler and WW II.