Some US Ships displace 104,000 tons with a full load such as the CVNs. Or do you mean U boats that can displace 19,000 tons such as the SSBNs. Or maybe you really mean boats like the RIB at about 1...
Originally when first built for Russia during the Russo-Japanese War in 1904, the U1 which was actually launched for the German Navy in 1906...displaced approximately 238 tons.
I Belive The "Unsinkable" Ship (Titanic) Weighs About 70,000 Tons
P.S To Find Out More About The Titanic Go To http://www.historyonthenet.com/titanic/unsinkable.html