Coates shielded his face when he entered an earlier court martial

Phillip Coates, from Devon, was jailed for five years in March after being found guilty of raping the woman at a barbecue on board a warship at sea.

The 30-year-old had also been dismissed from the service by the court martial panel at Portsmouth's HMS Nelson.

But three judges in London ruled that his conviction was unsafe.

Kissing admitted

It was believed Coates was the first sailor to be convicted for the alleged rape of a female colleague since women were allowed to go to sea with the Navy.

He was not present in court to hear Friday's ruling by Sir Igor Judge, Mr Justice Goldring and Mr Justice Beatson.

Coates, a married medical assistant, was also demoted and deprived of good conduct badges following the initial three-week trial.

The court martial had been told that the woman admitted kissing Coates prior to the alleged incident in the Mediterranean between 8 and 9 March last year.

But she insisted she had not consented to sex.