The Absolutely Fabulous star has a longstanding interest in the historic Biblical tale and dreamed of visiting Turkey's Mount Ararat, where the vessel is said to have come to rest.
However, access to the site is restricted, so Lumley devised a plan to film her expedition for TV to ensure she was allowed to visit.
She tells Britain's Sunday Telegraph, "It's such a complex, fascinating story. I wanted to take a look for myself, but I heard the site had been closed off to the public and was difficult to get to. So I thought, 'Well, if I wanted to try on the Crown Jewels, I'd be allowed to if I was making a film about them', and the same applied here. I'd be given access for a documentary. I thought, let's go for it."
Joanna Lumley's Ark will be screened on U.K. network ITV later this year (12).