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-...
The U.S. is so far ahead of the rest of the world in almost all defense technologies that it's a hard pill to swallow politically that there could be one relatively-small segment (non-nuclear surface warships) that we'd be better off actually buying from our closest allies.
We export so much defense equipment to our allies, that you'd think it would be okay to maybe possibly import one thing that's built better and cheaper elsewhere. But no, we'd rather subsidize our shipyards to continue churning out ships designed in the 1980s...
http://www.bls.gov/news.release/pdf/ichcc.pdf
If you have better data, I'm happy to take a look at them, but in my limited association with high-tech Japanese manufacturing this was basically the canonical example of "Ridiculously untrue things the Americans believe about us."
It's roughly analogous as if the rise of Honda and Toyota in the 1960s ran all the U.S. car manufacturers out of business.
On the other hand, there's plenty of competing companies that could bail out / buy (parts of) Google (or some other company) if they got into trouble - see MySpace and Digg and major web companies like that that became obsolete and effectively went out of business.