Hundreds of ferry passengers returning to Harwich from Holland were in a race against time overnight to beat the government's new quarantine rules.
The 120-mile journey usually takes eight and half hours, but the captain of the 'Stena Hollandica' sped up to reach the Essex port with just 30 minutes to spare, beating the 4am deadline.
The 64,000 tonne ship can carry up to 1,200 passengers.
There had been some confusion about whether the passengers would have to quarantine when arriving.
The ferry officially ties up at Harwich at 6.30am after leaving the Hook at 10pm and sails into UK territorial waters at 3am.
But officials at the Department for Transport insisted the deadline referred to the time the ship arrived at the docks, not when it entered UK waters.
"The short notice of the impending quarantine caught a lot of travellers out", a Stena spokesman said.
"Our afternoon ferry, the last one scheduled to arrive before quarantine, then filled up very quickly - not helped by restrictions on passenger numbers to allow for social distancing.
"A lot of people were panicking and for many there would be financial implications from quarantine: lost work, even lost jobs, or penalties from schools from kids staying home. There was a mad scrambling for alternatives to get them back before 4am."
People arriving from the Netherland after 4am on Saturday will be required to spend 14 days in self-isolation.
The decision to add the Netherlands to the list came after an increase in newly-reported coronavirus cases.
Travellers also returning from France, Monaco, Malta, Turks and Caicos, and Aruba will need to quarantine.