Gillian Anderson joins co-star Jason Isaacs on the set of The Salt Path in Cornwall

Filming for Gillian Anderson and Jason Isaacs’ new film The Salt Path is in full swing in Cornwall’s Holywell Bay.

The actress, 54, took a dip in the sea before sharing a sweet moment with the Harry Potter star, 60, on Sunday.

Gillian was seen in a nude long-sleeved top and striped pajama bottoms that had been splashed with the salt water.

Her damp blonde hair was styled in sultry waves as Jason gave her a kiss on the head between takes.

Meanwhile, the actor sported a full gray beard and hair and wore a casual black T-shirt with loose-fitting pants while getting into character.

At work: Filming for Gillian Anderson, 54, and Jason Isaacs’ new film The Salt Path is well underway in Cornwall’s Holywell Bay

Adorable: The actress took a dip in the sea before sharing a sweet moment with the Harry Potter star, 60, on Sunday

Adorable: The actress took a dip in the sea before sharing a sweet moment with the Harry Potter star, 60, on Sunday

Gillian and Jason later wrapped up warm in fleece ponchos and enjoyed a hot drink from a bottle.

The Salt Path is the film adaptation of Raynor Winn’s bestseller of the same name.

It tells the profound, true story of Raynor and her husband Moth, who decided to embark on a 630-mile trek along the Cornish, Devon and Dorset coastline.

The couple sadly became homeless in their 50s after a business deal with a friend fell through and they lost the farm in Wales where they raised their two children.

Their situation was then worsened when Moth was diagnosed with corticobasal degeneration, a rare and incurable degenerative brain disease.

They decided to walk the South West Coast Path and lived on the bare necessities with only a tent to shelter in.

The pair soon rediscovered their happiness, with Moth’s condition actually improving as they made the challenging journey.

Raynor decided to write an account of their story, originally intended just for her husband as a birthday present.

Stunning: Gillian wore a nude long-sleeved top and striped pajama bottoms that had been splashed with the salt water

Stunning: Gillian wore a nude long-sleeved top and striped pajama bottoms that had been splashed with the salt water

Filming: Meanwhile, the actor sported a full gray beard and hair and wore a casual black T-shirt with loose-fitting pants as he got into character

Filming: Meanwhile, the actor sported a full gray beard and hair and wore a casual black T-shirt with loose-fitting pants as he got into character

Taking a break: Gillian and Jason later wrapped up warm in fleece ponchos and enjoyed a hot drink from a bottle

Taking a break: Gillian and Jason later wrapped up warm in fleece ponchos and enjoyed a hot drink from a bottle

All smileys: her damp blonde hair was styled in sultry waves

All smileys: her damp blonde hair was styled in sultry waves

Tough: Gillian struggled with their tent during the scenes

Tough: Gillian struggled with their tent during the scenes

Her novel Het Zoutpad was published in 2018 and quickly skyrocketed to the top of the bestseller lists, selling more than 1.5 million copies.

It would go on to be shortlisted for the Costa Book Awards and the Wainwright Prize, winning the inaugural RSL Christopher Bland Prize.

Writing for The Mail On Sunday earlier this year, Raynor said their journey on The Salt Path made them feel more connected to nature.

She added, “And somehow, without us realizing it, the fear and despair, left behind on the many headlands we had crossed, had disappeared too.”

Coming soon: The Salt Path is the film adaptation of Raynor Winn's bestseller of the same name

Coming soon: The Salt Path is the film adaptation of Raynor Winn’s bestseller of the same name

Inspirational: It tells the profound true story of Raynor and her husband Moth, who decided to embark on a 630 mile trek along the Cornish, Devon and Dorset coastline (pictured in December)

Inspirational: It tells the profound true story of Raynor and her husband Moth, who decided to embark on a 630 mile trek along the Cornish, Devon and Dorset coastline (pictured in December)

Terrible: The couple sadly became homeless in their 50s after a business deal with a friend fell through and they lost the farm in Wales where they raised their two children

Terrible: The couple sadly became homeless in their 50s after a business deal with a friend fell through and they lost the farm in Wales where they raised their two children

Events: Their situation then worsened when Moth was diagnosed with corticobasal degeneration, a rare and incurable degenerative brain disease

Events: Their situation then worsened when Moth was diagnosed with corticobasal degeneration, a rare and incurable degenerative brain disease

Life Story: They decided to walk the South West Coast Path and lived on the bare necessities with only a tent to shelter in

Life Story: They decided to walk the South West Coast Path and lived on the bare necessities with only a tent to shelter in

In fact, the pair soon rediscovered their happiness, with Moth's condition actually improving as they made the challenging journey

In fact, the pair soon rediscovered their happiness, with Moth’s condition actually improving as they made the challenging journey

She wrote that she and Moth had not only “survived” their homeless experience, but had become “stronger for it.”

Raynor continued, “We all have the capacity to change and embrace a new future. We just have to act.’

The film adaptation stars Gillian and Jason as Raynor and Moth and is directed by Marianne Elliott.

Gillian tweeted that she “couldn’t wait to get started on the project” and called the novel a “great book.”