The 65-year-old woman was found by fishermen, shivering and clinging to her handbag some 500 metres out to sea.
The tourist had reportedly left the Marco Polo ship in the port of Funchal in Madeira, with her husband.
The couple were on day 28 of a 32-day voyage from the West Indies, but had decided to cut short the sailing after an argument.
Unbeknownst to the woman, her husband boarded a flight back to the UK, but the couple are thought to have become separated at the airport.
Thinking that he had returned to the ship, she is believed to have jumped into the water to try and swim to the ship herself.
However she quickly got into trouble and fishermen came to her rescue after hearing her screams.
Port boss Captain Felix Marques said she was clutching a bag, and was shivering from the cold, Sky News reported.
She was taken by ambulance to the local hospital, but her condition is not thought to be serious.
The Marco Polo was due to dock in Lisbon this morning. The ship’s captain was contacted and informed of the incident.
Her husband is expected to travel back to Funchal to be with his wife.
