I am a sucker for old maps and charts. If you put your harbor in to the search it will return all old versions of the chart/s for that area. I entered Castine and found copies of charts going back to 1881! How cool is that! Downloadable and printable too!

Here is the link with a warning, it is easy to get stuck going back in time.....

http://historicalcharts.noaa.gov/