An award-winning actor and former Olympic champion visited a Kent beach in preparation for a charity event this weekend.

Grantchester and Happy Valley star James Norton joined gold medallist Rebecca Adlington on Friday to kick off proceedings from Joss Bay in Broadstairs.

The pair are taking part in the Talisker Wild Blue Swim Challenge – a 10-hour ocean relay in aid of the Blue Marine Foundation.

The charity aims to protect and restore marine environments such as coastal habitats by addressing issues such as overfishing.

At 7am on Friday, swimmers began plunging into the cold waters for the endurance challenge ahead of World Ocean Day on Sunday.

Over a marked 100km course, swimmers will work as a team to clock up the distance over the 10 hours.

Ms Adlington won gold at the 2008 Beijing Olympics in the 400-metre freestyle and 800-metre freestyle, before claiming two bronze medals in the same events in London four years later.

She is also a World Championship, European Championship, and Commonwealth Games gold medalist, having scooped the medals before she retired from the sport aged 23 in 2013.

The 36-year-old told KMTV today: “It's absolutely incredible to be down here at Joss Bay.

“I've never been here before, so it's an absolutely incredible, incredible spot to be taking part.

“I am not an experienced sea swimmer, and I feel like throughout every time I've got in today I've just built in loads of confidence and just feel a lot more comfortable being in the sea.

“I've had my days of doing the competitive stuff so now I want to do stuff that's really meaningful and worthwhile.

“It’s about raising vital funds and awareness of the Blue Marine Foundation and the incredible work that they're doing.

“When you're doing the swim and it's cold and you're getting to the point where you're kind of battling a little bit, you just tell yourself what we're here for and how much it's going to help for that ocean restoration as well so it's just incredible.

“I was lucky enough to go in with James Norton at lunchtime which was just an incredible experience. He's so used to the ocean and the cold water, so I think he was helping me more than I was helping him.

“It's just been a fantastic day, full of fantastic people, a great cause.”

The pair's appearance – alongside other swimmers – will see Scottish whisky producer Talisker donate £150 to Blue Marine Foundation for every kilometre swum in total by participants.

These funds will go towards funding vital projects focused on improving water quality and restoring biodiversity to help return wildlife to coastlines.

Ellie Deans, head of Talisker, said: “Talisker has launched a new bottle called the Wild Blue in collaboration with the Blue Marine Foundation, all designed to raise awareness and money for the important work they do protecting and preserving the coastal habitats in the UK.

“For every bottle of Talisker the Wild Blue, £3 is donated to the Blue Marine Foundation and then we also have the swimmers for every collective kilometre swum, a further £150 is being donated to the Blue Marine Foundation.

“We're already at a total of over £100,000.

“Talisker is based up in the Isle of Skye but we think it's really important that we make sure the whole of the great British public are aware of the important work that we're doing with Blue Marine Foundation.

“Joss Bay is such a beautiful example of what it means to get outside in the UK and experience the beautiful sea that we have right here on our own coastline. Kent has been a wonderful host for us.”

Matt Uttley from the Blue Marine Foundation added: “It's huge for us to have an event like this going on.

“Marine Foundation is all about restoring nature, bringing the ocean back to health, but to do that we need people and we need people to be engaged and involved.

“One of the biggest problems that we face in marine restoration is that it's out of sight, you can't see the habitats that we're restoring.

“So bringing people down to the beach here, having everyone swim, get in the ocean, feeling the waves on you, you can really get at one with nature.”