Bikini-clad Tamara Ecclestone enjoys life in the slow lane as she cruises the French Riviera

Just last weekend,Tamara Ecclestone was surrounded by race cars speeding at the British Grand Prix.

But the model has definitely taken things slowly now as she cruises the French Riviera.

Showing off her amazing figure in a series of bikinis, the 27-year-old joined her boyfriend Omar Khyami, younger sister Petra and her fiancé for a luxury cruise.

Svelte: Tamara Ecclestone shows off her amazing figure in a blue striped bikini (left), before changing into a yellow and orange two-piece later on as she relaxes on her yacht near St Tropez, France

Recently unveiled as the face and body of Ultimo swimwear and evening gowns, Tamara flaunted her figure in a blue striped two-piece before changing into an orange and yellow number.

With Petra and fiance James Stunt apparently elsewhere, Tamara cuddled up to her boyfriend Omar, 37, who she has been dating since last year.

The two couples are enjoying a summer holiday ahead of blonde Petra's wedding to James Stunt in Italy next month.

Close: Tamara was very affectionate with her boyfriend Omar Khyami

This is the life: Tamara has been keeping followers updated with her holiday exploits on her Twitter page

And while Petra is getting married at the tender age of 22, it looks like she's in no hurry to settle down.

After spending their days working on their tans, the multi-millionairess siblings have been hitting the nightclubs of St Tropez at night.

As well as sunbathing on their chartered yacht, the girls have been indulging in plenty of pampering, enjoy manicures, pedicures and blow-drys before their partying.

Bride to be: Tamara posted a photo of her younger sister Petra in a neon bikini

Wild thing: Tamara wore an animal-print bikini on Tuesday

On Wednesday night, they saw David Guetta DJing and watched R&B singer Akon performing at VIP Club last night.

Throughout Wednesday's festivities, Tamara Tweeted about her partying: 'Shots have started!!!!... David Guetta OMG Amazing... After drinking kettle one grey gooose is undrinkable!... Ok maybe not undrinkable.'

Meanwhile, Petra and Stunt will marry in Odescalchi Castle near Rome during the August bank holiday weekend.

Ready to party: The Ecclestone sisters on their yacht before disembarking for the David Guetta DJ gig

The 15th century castle is the same venue where Tom Cruise wed Katie Holmes in 2006.

The sisters and their men arrived on the French Riveira on Monday after a busy weekend.

While Tamara was bringing sick children from Great Ormond Street Hospital to the British Grand Prix at Silverstone, Petra was being christened in a London church with just her fiance and mother Slavica present.

Her 28-year-old fiancé told the Mail's Richard Kay: 'Petra wasn’t christened as a baby and wants to do it now before our wedding so that everything can be done properly.'

Cover up: Tamara wore a long sundress as she and Omar boarded a speedboat back to the mainland - which was filmed by a TV crew