Nomadic arrived in Cherbourg on 3 June 1911 to begin her tendering duties for the White Star Line. On 10 April 1912 she transported 274 passengers to RMS Titanic for the doomed liner's maiden voyage, including Sir Cosmo Duff Gordon and his wife, Lucy (Lady Duff-Gordon), Denver millionaire Margaret Brown and industrialist Benjamin Guggenheim.
During World War I and until 1919, Nomadic was requisitioned by the French government and she saw service as an auxiliary minesweeper and patrol ship, also ferrying American troops to and from the harbor in Brest (France). After the war, she returned to her tendering duties, but in 1927 she was sold and continued to tender under the ownership of the Compagnie Cherbourgeoise de Transbordement.
Following the 1934 merger of White Star and Cunard Line and the opening of the enlarged port at Cherbourg, Nomadic ceased her tendering duties. She was sold to the Société Cherbourgeoise de Sauvetage et de Remorquage (SCSR or Cherbourg Tow & Rescue Society) and renamed Ingenieur Minard.
During World War II, Nomadic again saw service; on 18 June 1940 she took part in the evacuation of Cherbourg. She was subsequently requisitioned by the Royal Navy and based in Portsmouth harbor, she operated as a troop ship, coastal patrol vessel and minelayer for the remainder of the war.
During the war, Cherbourg port was heavily damaged, so large ocean liners could no longer dock there. Nomadic was saved from scrap and again returned to tendering duties for the SCSR from Cherbourg. She served the great ocean liners of the day, such as the Queen Mary and the Queen Elizabeth. She finally retired from these duties on 4 November 1968.
Nomadic lay idle for five years but was subsequently bought by a private individual, Yvon Vincent, saving her from scrap once again. She was extensively converted into a floating restaurant and function vessel, and in October 1974 was relocated to the Seine in Paris. By 1999, the business was in financial difficulties and Nomadic was seized by the Paris harbor authorities in 2002. The authorities removed some of Nomadic's superstructure in order to tow her below the Seine's bridges. On 1 April 2003 she was towed out of Paris to Le Havre.
Following Vincent’s death in March 2005, the authorities sought to dispose of the vessel and attempted to find a buyer for Nomadic, if no buyer was found, she risked being sold for scrap value. On learning of her fate, heritage and maritime enthusiasts (including the French Titanic Society, Belfast Industrial Heritage, Belfast Titanic Society and the Save Nomadic appeal) began campaigns to raise funds to buy the vessel. These campaigns were well supported by the public, particularly in Northern Ireland, but were unable to raise sufficient funds to meet Nomadic's reserve price.
The campaigns however gained political and governmental support, and on 26 January 2006, the Northern Ireland government Department for Social Development bought the vessel at auction for €250,001 (the reserve price being €250,000).
SS Nomadic left Le Havre to return to Belfast on 12 July 2006, and arrived close to where she was built, on 18 July 2006. The vessel was welcomed back by the Department for Social Development Minister, David Hanson MP and the Deputy Lord Mayor of the City of Belfast, Ruth Patterson and a number of well wishers. Nomadic arrived "piggy backed" on a marine transportation barge, which had been contracted by the department.