The British woman – only known as ‘Kay’ – fell overboard the Norwegian Star Ship while it was sailing from Port of Vargarola near Pula, Croatia.
She fell off the ship shortly before midnight on Saturday, launching a desperate search in the dark waters.
Incredibly, she was found 10 hours later treading water not far from where she is believed to have fallen.
Speaking to The Sun, the 46-year-old said: ‘I fell off the back of the Norwegian Star and I was in the water for about 10 hours. These wonderful guys rescued me.’
When asked how she survived so long in the water alone, Kay credited ‘singing and yoga’.
Croatian authorities said it is unclear if the woman accidentally went overboard and are yet to examine CCTV footage.
The woman was taken to hospital and is believed to be safe and well.