I promised you I would try to track down my figure for the mileage of the coast, and I think I have finally found my source, and the source of my source.
While at the Maine Boatbuilders Show this spring I asked David Platt of the Island Institute if they had, indeed, published the results of the newer GIS surveys of the coast's length. He said that they had, and that the latest surveys put it at near 7,000 miles (but don't quote me on this!). The man responsible for the surveys is someone at the College of the Atlantic. David didn't know his name, but said you could reach him by asking for the "GIS guy."