Shipbuilding was excluded from the North American Free Trade Agreement, essentially because of an American regulation called the Jones Act. It states that in order to build a ship to be used within the United States, it must be built in the United States, crewed in the United States, and owned by an American. Therefore, we are not able to access their commercial market in any way for those ships.
On September 29th, 2011. See this statement in context.