Apparently up until 1981, the US had the Construction differential subsidy program [1][2] that subsided shipbuilding construction. During the Regan administration, the US eliminated subsidies whereas countries in Asia did not. Now the top 10 shipbuilding countries are in China, Korea, or Japan [3][4].

Outside of a few exceptions, such as a 1920 law forcing US-based natural gas to only be transported on American made/manned ships [5], the US shipbuilding industry has one customer: the military. Without additional subsidies it's unlikely the US can effectively compete with places like China, which continue to increase subsidies for shipbuilders [6].

In this political climate (especially post-Solyndra, post ethanol-subsidy) I think it's unlikely the federal government would increase subsidies for a private industry. On one hand, this might not be a bad thing: Chinese-subsidized industries don't always work out the way they planned (e.g., the construction of ghost towns). However if the military doesn't keep the industry up-to-date technologically, a shipbuilding tech gap could form, which might impact national security.

[1] http://en.wikipedia.org/wiki/Long_Range_Shipbuilding_Program

[2] http://www.marinelink.com/article/shipbuilding/the-future-am...

[3] http://www.marineinsight.com/marine/marine-news/headline/top...

[4] http://thediplomat.com/2012/11/u-s-navy-take-notice-china-is...

[5] http://www.foxnews.com/us/2013/09/20/boom-in-natural-gas-pro...

[6] http://www.reuters.com/article/2013/12/09/us-china-shipping-...