Airports in parts of Scotland and Northern Ireland closed from 0700 BST because of risks from volcanic ash.
Glasgow, Prestwick and Derry are likely to be closed all day, while there are plans to shut Inverness in the morning only, and Belfast in the afternoon. The CAA advised air passengers to check with airports before travelling and warned the situation was changeable. Last month, volcanic ash clouds from Iceland grounded flights for six days. The situation in the skies has been changing hour by hour, meaning the picture for air travellers is unclear. Dublin Airport will also close from 1100 BST until further notice.
However, the latest advice issued by the CAA at 0200 BST said airports in Edinburgh and north-west England could safely stay open on Wednesday, despite the proximity of the ash. Earlier forecasts also suggested higher ash levels were drifting southwards, but the CAA says the South East of England is unlikely to be affected on Wednesday.
So if you are flying out to meet a Cruise ship in the next few days, please check with your air carrier to see the status of your flights.