A ferry carrying 489 passengers has struck the quay and started to let in water.
The Sirena Seaways ferry struck the quay at Parkeston near Harwich in Essex just after midday, but the water it was taking on was "quickly stopped".
The master of the ferry is currently in talks with engineers, coastguard and the harbour authority about how they will tow the vessel into the harbour.
There are no reported injuries and no reported pollution, Thames Coastguard said.
Essex County Fire and Rescue Service said that "no-one is trapped" and "there are no casualties", but said there has been "damage to the ship under the water line".
In an incident report, the service said
"The passengers and their vehicles are still on board but in no danger and the vessel will shortly be re-berthed so that they can continue their journey."
Meanwhile, Terry Jewell, station officer, said: "This is one of the regular ferries that comes into Harwich and as it docked it hit the side of the quay making a hole under the water line.
"The ship is stable now and we are standing by as a precaution while the vessel is moved so that ramps can come down and passengers can leave.
"The ship's crew worked swiftly to put their safety plans into practice immediately after the accident happened."