The recent disruption to global air travel has reminded travelers that, while it may take longer, travel by sea is reliable and enjoyable.

With flights across Europe grounded and the prospect of further volcanic ash to come, something of a renaissance may be underway in the way we travel.

Passengers have been increasingly reliant on alternative modes of transportation - and since busy crossings such as the English Channel and Atlantic Ocean have become no-fly zones, they have turned to ships.

Cunard, which has operated a transatlantic crossing using cruise ships since 1840, says that its seven-day 3,000-passenger Southampton - New York crossing on Thursday April 22 is now fully booked, but passengers can join a wait list. The next scheduled voyage will leave on Thursday April 29, and is also sold out with a wait list.

Princess Cruises, which will sail a 28-day cruise from Fort Lauderdale in the US to Copenhagen in Denmark on April 26 via Portugal, Spain, France, the Netherlands and Belgium, says that it is experiencing "unprecedented demand" for transatlantic cruises from the US.

Meanwhile, the maiden cruise of the Celebrity Eclipse, a brand new 122,000-ton liner, has been put on hold so that the ship can set sail for Spain, where it will pick up stranded British and Irish tourists. The ship's owner Celebrity Cruises is working with major tour operators to try to assist with getting passengers, some of whom flew into Europe using Madrid as it was the nearest available airport, to their destinations.

"The events affecting air travel are completely unprecedented, and it is in times like these that the global travel industry needs to pull together," said Richard D. Fain, chairman of Celebrity Cruises.

Cruise and Maritime Voyages, which operates liners within Europe, says that the demand for last minute travel has surged and that it is "flat-out answering calls."

Commercial ferry operators in Spain have said that they are now fully booked until next Thursday and hundreds were turned away by a British Navy vessel, which only had capacity to carry 200 people identified as vulnerable by officials.

Ferry companies in Britain and France have also increased cross channel capacity to ease the backlog of thousands of travellers. P&O Ferries said that it had experienced ten times the number of daily bookings than was usual for this time of year. It is currently reporting, however, that there is limited space available for passengers.