Silversea is introducing a series of ‘backward’ sailings after research suggested the ships would be more energy efficient if constantly in reverse.

The move comes after a research study conducted by the Institute of Backward Thinking revealed that a surprising combination of tides, aerodynamics and unintentional ship design had conspired to create this phenomenon.

A spokesman from the institute said: “This won’t work on all routes, and on some it will have more of an impact than others.

“Through a series of calculations taking into account the distance of a particular section of the ocean from the moon at certain times of the year we can see where sailing in reverse will do the greatest good.

“When we discovered this we went straight to Silversea to ask for their help in testing the theory because their ships are best equipped to sail backwards – and we were proved correct.”

The ultra luxury cruise line will be running a small number of backward cruises in 2012 to see how customers react but hopes to increase the number in 2013.

A Silversea spokesman said: “As you can imagine we were a little taken aback at first but couldn’t ignore it when the facts were all there laid out in front of us.

“Our captains are so skilled that this isn’t a problem for them and of course most sailing is not done with the eyes any more.

“We are going to install large wing mirrors on the side of the ship as a precaution but don’t expect them to be used very often.”

The initial reaction from past guests has been positive according to Silversea.

“Our repeat guests especially are looking forward to trying something a little different,” the spokesman added.

Training on selling backward sailings will be conducted at the lines series of events taking place this year.