Kendall Jenner and Hailey Bieber are doing what models do best in the summer.

The bikini-clad besties were photographed enjoying a yacht day in Cabo San Lucas, Mexico, with two of their equally beautiful girlfriends: Lori Harvey and Justine Skye.

For the lavish yet relaxing outing, the group wore tiny swimsuits, soaked up the sun, took dips in the crystal-clear water, rinsed off at the onboard shower station and sipped on Jenner’s 818 Tequila.

Jenner, 27, rocked a slinky, snakeskin two-piece with small hoop earrings and black sunglasses, later modeling a cowboy hat.

Kendall Jenner
Kendall Jenner and Hailey Bieber spent a day on a yacht with Lori Harvey and Justine Skye.Instagram

Kendall Jenner
The fabulous foursome was photographed sailing in Cabo San Lucas, Mexico.Instagram

Hailey Bieber
The group wore tiny swimsuits, soaked up the sun and took dips in the crystal-clear water.Instagram

Hailey Bieber
They also sipped on Jenner’s 818 Tequila.Instagram
With a bottle of her liquor in hand, the “Kardashians” star smiled as she poured shots for her pals – and even directly from the bottle into their mouths.

Bieber, 26, stunned in a bright blue string bikini with white accents, completing her seaside look with small hoop earrings and a statement necklace featuring the letter B.

At one point, she also sported a daisy-printed bucket hat.

The very tan wife of pop star Justin Bieber was snapped happily throwing back a shot of tequila as Harvey, 26, looked on.

The daughter of famed TV host Steve Harvey sported an orange crisscross bathing suit top and white bottoms – perhaps from her newly launched line, Yevrah – and finished off her look with chic shades, small hoop earrings and her hair styled in braids.

Lori Harvey
Paparazzi snapped them taking turns rinsing off at the onboard shower station.Instagram

Lori Harvey
The girlfriends made sure to document their boujee afternoon with various photo shoots captured by their respective cellphones.Instagram

Justine Skye
Skye celebrated her 28th birthday aboard the luxury boat.Instagram

Justine Skye
She posed in front of a decorated cake topped with a massive sparkling candle.Instagram
Meanwhile, Skye opted for a flower-patterned bralette-style top and matching high-waisted bottoms, which she paired with a blue headband and stud earrings.

The songstress celebrated her 28th birthday aboard the luxury boat, as social media photos show her posing in front of a decorated cake topped with a massive sparkling candle.

The fabulous foursome made sure to document their boujee afternoon with various photo shoots captured by their respective cellphones.