While son Arkady tucked into an ice-cream treat, the glamorous blonde - svelte in a gold skirt and yellow vest - held the hand of her youngest child, three-year-old Ilya. The family, who had a guide with them, were exploring the sights of the charming cobbled streets, such as the Onofrio Fountain - which dates from 1483 - the Sponza Palace and the remarkably preserved city walls, some of which were constructed in the 13th century.
With the Pelorus at their disposition the family had no need for a hotel, enjoying instead the luxury vessel's five-star facilities. Meanwhile, Irina's ex, whom she divorced earlier this year, is enjoying a break of his own aboard another of his extensive collection of yachts - the Ecstasea.
And the billionaire owner of Chelsea football club is about to add yet another vessel to his fleet of floating palaces. The Eclipse - currently being built in Germany at a reported cost of £200 million - will be the world's largest private yacht.