The Plymouth-based company traded under the names Blue O2, Blue O Two, blue o two and blueotwo, as well as the website blueotwo.com.

But the Blue O Two brand will continue to operate under the ownership of Scuba Tours Worldwide Limited.

“If you are currently overseas, it is our understanding that all elements remain valid, and your booking will proceed as planned,” said the CAA in a statement.

“Bookings which do not include a flight element are not covered by the Atol scheme, however it is our understanding that your booking will not be affected unless you have received notification to the contrary from the company’s administrators.”

A statement from Blue 02 Limited said: “Although we were granted a new license to provide packages including flights, the CAA, with consumers best interests in mind, imposed conditions on Blue 02 Limited’s Atol license.

“This, as well as refunding many millions of pounds, has made it difficult for the directors to see a way forward for Blue 02 Ltd which protects the interests of our customers in the current Covid climate.

“Given the financial damage caused by the pandemic, and despite our relentless best efforts to save Blue 02 Ltd, unfortunately, and with regret, the decision was made to cease trading on 15 November 2021.

“We are delighted to say that the Blue O Two brand lives on under Scuba Tours Worldwide Limited – which now trades as Blue O Two. We will continue to operate and provide scuba diving liveaboard holidays with the same devoted team of people.

“As such, we will be able to provide some existing holidays booked with Blue 02 Limited as planned, to some customers.”