Most of the year, Bath Iron Works (700 Washington St., Bath, 207/443-3311, www.gdbiw.com [1]) is off-limits to the public. That changes during one of its infrequent but spectacular ship launchings. Then the whole town comes out for the celebration and flags, food, and local dignitaries fill the waterfront to break champagne on the hull.
Links:
[1] http://www.gdbiw.com