Earlier quoted context omitted.
In the U.S. yes, but this is in Ecuador. Such a company would operate wholly outside the U.S., and only sell the submarines in kit form, ready for assembly. Here's the full text of the law b.t.w.: http://www.gpo.gov/fdsys/pkg/PLAW-110publ407/html/PLAW-110pu...
As soon as a sub comes into international waters the law applies. I see no reason why the interpretation of "conspiring" would be hindered by kit-form subs or sovereignty of the manufacturing location. If there was a thriving market for cargo submarines for non-covert haulage, maybe. I suppose if the shipyard owners don't do too many subs, don't travel internationally, and the country doesn't extradite to the United…
Edit: the US law intends to apply to vessels "without nationality", but I'm pretty sure the crew has a nationality which might want to object.
Most other nations would at least release a statement against such practices by the US (I know mine would, heck I'd draft it myself)