An update from the Maritime and Coastguard Agency says that 10 people have been injured, and that most are showing signs of hypothermia.
The statement continued: "It's believed that all those in the water have been accounted for. However rescue units on scene, including the helicopters and lifeboats, are carrying out further searches to make sure."
More top news
Foreign Secretary Philip Hammond said there will have to be a "trade-off" on access to the EU single market and migration controls.