This video shows the details of what happens when a huge (400 metre long) container ship leaves the quay when she has completed a port call. The mooring gang let go of the mooring lines, the bow tug (Svitzer Sky) makes her towrope fast to the ship, and when the moorings are clear, it all happens. The pilot, who you can see on the ship's bridge, with the ship's master, instructs the tugs, and the ship is moved to a position from which it can safely get under way.
The ship is the CSCL Atlantic Ocean, an ultra large container ship of 400 metres length, 59 metres beam. She can carry 19,000 TEU of containers, and arrived at Felixstowe directly from Singapore via the Suez Canal. Her next call will be at Gdansk, Poland
This clip is 720 resolution; it is also available in 1080