PICTURE EXCLUSIVE: Hailey Baldwin looks stunning in tiny polka dot bikini on yacht with pals Kylie and Kendall Jenner... before taking a daring leap into the sea

She's part of one of the most close-knit groups in celebrity circles.

So it's no surprise Hailey Baldwin looked overjoyed as she was able to join her best pals on a luxury yacht to celebrate Kylie Jenner's 18th birthday in Mexico on Wednesday.

The 18-year-old model displayed her impeccable bikini body as she relaxed on the liner with her friends, before then showing off her daredevil bravery by leaping from the very top.

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Holiday fun: Hailey Baldwin joined Kylie Jenner in Mexico on Wednesday, as the Keeping Up With The Kardashains star continues her 18th birthday celebrations

Holiday fun: Hailey Baldwin joined Kylie Jenner in Mexico on Wednesday, as the Keeping Up With The Kardashains star continues her 18th birthday celebrations

Wearing a pale brown and white polka dot two-piece swimsuit with a delicate crossover strappy back, the slender star flaunted her petite curves and ample chest under the baking midday sun.

As she turned around, she also revealed the tiny briefs to be very high-cut, showing much of her pert derriere. 

With her trim, toned abs and shapely legs on show in the skimpy swimsuit, she proved her model credentials while also going make-up free and looking naturally gorgeous.

Her wet hair fuss-free and slicked back off her face, curling slightly as it dried down her back.

Bikini body win: The 18-year-old proved her model credentials as she donned a tiny pale brown and white polka dot bikini while relaxing on filmmaker Joe Francis' yacht with the group

Bikini body win: The 18-year-old proved her model credentials as she donned a tiny pale brown and white polka dot bikini while relaxing on filmmaker Joe Francis' yacht with the group

Getting ready: Chatting away to best pal Kendall Jenner, Hailey prepared to climb onto the roof of the small watercraft

Getting ready: Chatting away to best pal Kendall Jenner, Hailey prepared to climb onto the roof of the small watercraft

Happy to be here! The stunning star - who went make-up free and with her hair slicked back from the sea water - flashed a smile as she crawled up the curved panel

Happy to be here! The stunning star - who went make-up free and with her hair slicked back from the sea water - flashed a smile as she crawled up the curved panel

And... jump! With her friends looking on, Hailey bravely took a daredevil leap into the ocean from the roof

And... jump! With her friends looking on, Hailey bravely took a daredevil leap into the ocean from the roof

Be on board with Hailey's style in a polka dot bikini by Acacia

Between Hailey Baldwin and her BFFs the Jenner sisters, there was no shortage of swimwear inspiration for us when they were spotted celebrating Kylie's 18th birthday on board a luxury yacht.

She showed off her incredible figure in a grey and white two-piece bikini, which is by celebrity favorite brand Acacia. Check out the cheeky cut and chevron panel on the bottoms, as well as the strappy back top of this two-piece. It's safe to say we'd all like to be in Hailey's boat!

Click right to get yours now from ISHINE365.

Alternatively, get a piece of the polka dot pie with the help of our edit below. Topshop's mismatched style does all the hard work for you, or we love the playful print on this Asos option.

* PRICES MAY NOT BE AS ADVERTISED

But, as well as exhibiting her envy-inducing frame on the yacht filled with gorgeous young ladies, Hailey decided it was also time to do something reckless, as she climbed on top of the roof of the small yacht.

With birthday girl Kylie, her sister Kendall Jenner, 19, and their other party-going friends looking on, the daughter of actor Stephen Baldwin posed up a storm before taking a huge leap into the sea.

She landed safely, however, and made it back safely onto the boat to be with her gaggle of bikini-clad pals.

As well as Kylie and Kendall, Hailey joined their friend singer Pia Mia for the idyllic sun-soaked getaway, as well as Kylie's boyfriend Tyga, and entrepreneur Joe Francis.

Careful! The group - including singer Pia Mia and rapper Tyga - watched on as bikini-clad Hailey prepared for her leap

Careful! The group - including singer Pia Mia and rapper Tyga - watched on as bikini-clad Hailey prepared for her leap

Can she do it? Tyga (front, third from left) appeared to be pointing at the precarious distance between the roof and the sea

Can she do it? Tyga (front, third from left) appeared to be pointing at the precarious distance between the roof and the sea

Having a dance? While up at the top of the boat, Haliey was aided by a male pal, as she almost seemed to slip over

Having a dance? While up at the top of the boat, Haliey was aided by a male pal, as she almost seemed to slip over

Envy-inducing body: Meanwhile Kendall, 19, looked impeccable in a tiny crochet bikini as she took a more relaxed stance

Envy-inducing body: Meanwhile Kendall, 19, looked impeccable in a tiny crochet bikini as she took a more relaxed stance

He owns the beautiful oceanside property the group are enjoying this week, and also going along for the fun days-long party was his partner Abbey Wilson.

Following her lead, Kendall and Kylie also spent time leaping from the roof of the watercraft into the cooling ocean.

Girls Gone Wild creator Francis, 42, watched on nervously as his guests jumped into the chilly Pacific, but everyone was safe and sound after their thrill-seeking activities.

The birthday girl looked to be having a whale of a time on her celebratory bash in Mexico, opting for a halter-neck style white bikini top and high-cut white bottoms with a double strap.

Getaway fun: Kendall and Hailey were among a group of pals who had jetted to Girls Gone Wild creator Joe Francis' Mexico estate

Getaway fun: Kendall and Hailey were among a group of pals who had jetted to Girls Gone Wild creator Joe Francis' Mexico estate

Birthday fun: Kylie, 18, was the centre of attention as she mingled with her sister and friends during the boat party

Birthday fun: Kylie, 18, was the centre of attention as she mingled with her sister and friends during the boat party

Close-knit circle: There were just over 10 people enjoying themselves on Francis' yacht out to sea on Wednesday

Close-knit circle: There were just over 10 people enjoying themselves on Francis' yacht out to sea on Wednesday

Splash! Hailey later joined hands with singer pal Pia Mia as the two jumped into the sea, while sisters Kylie and Kendall looked on

Splash! Hailey later joined hands with singer pal Pia Mia as the two jumped into the sea, while sisters Kylie and Kendall looked on

Flying high! Hailey and Pia Mia showed off some impressive leaping skills

Flying high! Hailey and Pia Mia showed off some impressive leaping skills

She flaunted her ample curves in the two-piece on the deck of the yacht, her hair newly-styled into a thick cornrows for ease during the beachy getaway.

Kendall, meanwhile, looked incredible as she showed off her supermodel figure in a crochet bikini, invoking an effortless and almost bohemian vibe with her swimwear.

Hailey had gone along with best friend Kendall on Wednesday to join Kylie and the rest of the posse for her fun birthday getaway, after Kylie herself had jetted to Francis' private estate on Monday.

Celebrations: Kylie - wearing a tiny white halter-neck bikini and with her hair in cornrows - has been marking her milestone 18th birthday in style this week

Celebrations: Kylie - wearing a tiny white halter-neck bikini and with her hair in cornrows - has been marking her milestone 18th birthday in style this week

Fun in the sun: Hailey spent time sitting under the glorious Mexico weather on top of the boat (left), as Kylie preferred to take a dip in the sea (right)

Fun in the sun: Hailey spent time sitting under the glorious Mexico weather on top of the boat (left), as Kylie preferred to take a dip in the sea (right)

Keeping the party going: Kylie's 18th birthday was on Monday, but - along with her rumoured boyfriend Tyga and their friends - it looks to be a week-long celebration

Keeping the party going: Kylie's 18th birthday was on Monday, but - along with her rumoured boyfriend Tyga and their friends - it looks to be a week-long celebration

Francis regularly hosts the Kardashian clan at his stunning resort - with Kim, Kourtney and Khloe taking advantage of the luxurious 5-star Punta Mita amenities.

The beautiful accommodations boast 12 bedrooms, 13 bathrooms, 5-star executive chefs, a screening room, a gym, two pools and its own private beach.

Newly-renovated this year, Casa Aramara is nestled amid acres of lush tropical gardens offering peace and seclusion. 

Kylie's extravagant birthday celebrations kicked off in style on Sunday night, as she enjoyed a star-studded night out on the town with family and friends in Los Angeles.

She then wasted no time in flying out to Mexico, getting on a private let to fly in the lap of luxury for her holiday. 

Relaxation: Looking like a gorgeous bevy of babes, the bikini-clad group sunned themselves on the top deck

Relaxation: Looking like a gorgeous bevy of babes, the bikini-clad group sunned themselves on the top deck

What's over there? Kendall, Hailey, Kylie and Pia Mia looked overjoyed as they saw something amusing off in the distance

What's over there? Kendall, Hailey, Kylie and Pia Mia looked overjoyed as they saw something amusing off in the distance

To infinity, and beyond! Sisters Kylie and Kendall clutched hands with each other as they bravely took a giant leap into the Pacific

To infinity, and beyond! Sisters Kylie and Kendall clutched hands with each other as they bravely took a giant leap into the Pacific

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