The Duchess of Cornwall even admitted she was considering a swim.
'The temptation is great to have a quick dip like the Queen did,' she said.
Dench showed the duchess around Osborne House, a tour which included the newly restored Durbar Room, one of the locations for the film Victoria and Abdul in which the star played Queen Victoria.
'Ah, here you are, Judi,' Camilla said spotting an image of the actress taken while filming the movie.
Later, Judi and Camilla rode in a carriage and met excited fans.
'Going to Osborne House is always such a treat as it was built by my great-great grandfather and I feel very fond of the place,' the duchess said.
'To come and launch Red Funnel 7 was very exciting, and it worked! Last time I launched a ship in Southampton I pressed the button and nothing happened…so I was very pleased today it ran like clockwork! So, thank you all very much and I very much hope I shall be back soon, hopefully on a holiday.'
Dench and Camilla have met on several occasions before.