REALITY TV star Spencer Matthews has taken to the chilly waters of his family’s huge Scottish estate as he prepares for his next endurance challenge.

Mr Matthews, who is best known for his appearance on Made in Chelsea, swam the almost three-mile length of Loch Affric yesterday (Sat) in a training exercise.

Located 15 miles west of Loch Ness, the 10,000-acre Glen Affric estate is owned by Mr Matthews’ father David, who is also father-in-law to Pippa Middleton, sister of the Princess of Wales.

The 10,000 acre estate also includes the main house, Affric Lodge.

Sharing details of his achievement on social media, Mr Matthews said he had swam from the western shore of the loch to the eastern shore where the family’s lodge is based.

In a video, filmed as he paused mid-way through his swim, he said: ‘Good stuff.’

A companion, who had come out on a boat to check in with him, then asked how he was feeling.

In response, Matthews said: ‘Very good. I can’t speak properly. I’m slurring. Let’s go.’

Matthews, who is married to model Vogue Williams, then set off again to finish the remainder of his arduous swim.

The outing was part of Matthews training for his Project 7 challenge, which will see him complete seven full-distance Ironman-style triathlons on seven continents back to back.

Each leg of the 23-day Project 7 challenge consists of a 3.8km swim followed by a 180km bike ride and topped off with a full marathon – 42.2 km. Matthews will begin in South America then move through North America, Europe, Asia, Australia and Africa, finishing up in Antarctica.

Mr Matthews and his family make regular trips to his family’s Scottish estate.

The couple, who share three children: Theodore, six, Gigi, four, and two-year-old Otto, often share snippets on social media from their family holidays at Glen Affric, which Mrs Williams has described as one of their ‘favourite places’,

Known as the most beautiful glen in Scotland, Glen Affric is also garnering even more attention than usual as it forms the backdrop to a new drama starring Keira Knightley.

In the new Netflix sensation ‘The Woman in Cabin 10’ viewers believe they are being taken on a glamorous, nautical, voyage in search of the Northern Lights through the Norwegian fjords.

In reality, the dramatic conclusion to the murder / mystery takes place in Glen Affric.

Today, the estate used Instagram account to advertise its starring role in ‘The Woman in Cabin 10’, in which 40-year-old Knightley plays a journalist who thought she was on a fabulous ‘feeebie’ on a millionaire’s yacht.

The dramatic conclusion was filmed last November in a glass marquee, next to Affric Lodge, built in the late 19th Century and surrounded by the pines of the Caledonian Forest.

Knightley jetted in for her scenes, along with actors Hannah Waddingham and Guy Pearce, who plays ship’s host, Richard Bullmer.