wmur photo
Just after 2 pm this ship broke a mooring line or something and got loose from the State Pier in Portsmouth Harbor.
It is my understanding that another ship recently presented a real problem when docking. It was a bear to get this other ship snugged up to the pier. In that area, Portsmouth Harbor with those tides, you have to really be on the ball. I would think the Captain of the vessel is responsible for making sure his ship is secure.
Those with the local knowledge should be taking care of business too.
This is the 3rd incident where the tide has come into play . I am including the two recent tug mishaps that were due to insufficient attention being paid to mooring lines and the tide.
Route 1 is now closed as the bridge was damaged.
Mike
The Exeter Town Crier 
You can see the ship hit the bridge in the time lapse pictures from the tug webcam. It comes into harbor around noon, picture 48, and breaks loose around 1:15, picture 53. The time lapse video they have for the last 24 hours is pretty cool too, you can see the tide turn.
http://www.portsmouthwebcam.com/tugboats/2013_04_01/daily.htm