Unbelievable:Penny Lancaster, 53, wows in a tiny black bikini as she soaks up the sun with husband Rod Stewart, 79, on £50million yacht in Sardinia

Penny Lancaster dressed for the European heatwave as she set sail with husband Rob Stewart and their family in Sardinia.

The couple are enjoying a family break on a £50million yacht and as temperatures across the region hit the high 30s, Penny stripped down to a barely there black bikini.

The model, 53, looked incredible in the tiny halterneck bikini as she sunbathed on deck and chatted with her family.

Rod, 79, meanwhile tried to keep cool by draping a T-shirt over his head as he relaxed in a lemon yellow shirt and bold shorts.

Penny later swapped her bikini for a green and pink floral print cover-up as the family jumped on a dinghy to head to shore.

The Sailing singer has whisked most of his family away on the lavish holiday to Porto Cervo in Sardinia.

The rocker is enjoying the trip with six of his eight children, as well as his baby grandson Otis and several of his kids’ partners.

The blended family took to their Instagrams this week to share a slew of sweet snaps from the getaway.

One heartwarming shot showed Penny and Rod playing with one-year-old Otis on the boat, as the little boy burst into giggles.

The couple – who married in 2007 – were joined by their two sons Alastair Wallace, 18, and Aiden Patrick, 13, as well as Alastair’s girlfriend Eloise Darlington, 18.

Joining them were Kimberly, 44, and Sean, 43, — Rod’s two children from his marriage to actress Alana Stewart.

While his daughter from his relationship with model Kelly Emberg and Otis’ mother Ruby, 36, was there with her fiancé Jake Kalic.

And his daughter Renee, 32, from his marriage to actress Rachel Hunter was joined by her boyfriend Adam Sumner.

However, his other child with Rachel, son Liam, 29, was not seen in any photos, nor was his eldest child Sarah Streeter, 60, who he put up for adoption as a baby.

The Stewart clan could be seen enjoying several beers in the sun and going out for opulent dinners together.

The trip comes after Rod and Penny recently discussed the secrets to their loving and successful marriage and how they navigated the unique problems of living in a ‘blended family.’

Reflecting on their home life in a candid interview last week, the duo detailed how they ensure their relationship stays ‘special’ and bring up their brood to remain humble.

Speaking to HELLO!, Rod explained: ‘We listen to each other and try to resolve all our disagreements – the dirty laundry, as Penny says – right away, and before we go to bed.

When Penny met Rod back in 1999 when she performed as part of his band and he was still married to his second wife Rachel.

Rachel and Rod separated that year and divorced in 2006, with the singer going on to marry Penny in 2007.

At the time Rod already had six children, with Penny admitting: ‘I knew that I had to be honest with them, too, so that they would accept me. I couldn’t pretend to please every single one of them, so I was just myself. It took a while, but they came to trust me.’

Despite his huge fortune, Rod is determined to make sure his children remain humble, with his and Penny’s eldest, Alastair, driving a used Ford Fiesta.

He said: ‘As the saying goes, they know the value of a dollar. On his last birthday, we wanted to give him a new car, but he didn’t want it. I believe the children are genuinely grateful for the life they have.’