Hannah, from Twickenham, West ­London, said: “I was absolutely shattered when the coastguards came by – so much so that when I was told people had come aboard with guns I thought it was a joke.

“We couldn’t have looked less like ­illegal immigrants.”

Hannah’s dad Ian said: “The French police came on board and ordered us to put our hands up. I had to stop myself from laughing as it was so ­ridiculous.”

Chartered surveyor Hannah, 28, ­completed the 22-mile challenge on ­Tuesday for surveyors’ benevolent fund LionHeart and a hospice in Esher, Surrey.