It would be easier to transport a shipyard, work force and materials than a modular warship of any size.
See this link -
Liberty Ships Built During World War II Listed by Shipyard
http://www.usmm.org/libyards.htmlAnd in particular this one for St. Johns River Shipbuilding, Jacksonville, Florida.
http://www.usmm.org/l/southe.html#1221And see also this 1986 NY Times article on the last inland US shipyard.
http://www.nytimes.com/1986/06/10/us/an ... -ohio.html"The founder of shipbuilding in Jeffersonville, which today has about 20,000 residents, was James Howard, who came here from Cincinnati, and his Howard works became one of the most famous boat works in America, producing such steamboats as the Cape Girardeau, the Spread Eagle 4, the Ruth 2, the General Lee, the Belle of the Bends and the J. M. White 3, which riverboat historians say was probably the finest, fastest boat ever built for the Western river trade. As steamboating died out, work diminished at the Howard yards, and they closed in 1931.
The shipbuilding tradition was kept up when, in 1938, the Jefferson Boat and Machine Company, which later changed its name to Jeffboat, was formed, its waterfront location including the site of the old Howard works.
The United States Navy ran the yard in World War II, and the yard completed six towboats, 12 tankers, 8 submarine chasers and 123 landing ships for tanks."