By now, we are all familiar with the equestrian status of supermodels Gigi and Bella Hadid. They are horse girls, and they are proud.

But what's a supermodel horse girl to do when she's on vacation with nary a barn is in sight?

It seems, for the Hadid sisters at least, that the answer is jet skis. Last month, the two were spotted on vacation in Greece. Gigi (who was dubbed Mykonos "Gíkonos" during this holiday) was seen on a jet ski jaunt around the island.

This isn't a new hobby. Last summer she rode a red and white jet ski under the Grecian sun.

And, in a luxe twist, Gigi also climbed aboard a Fendi-printed version for the cover of V magazine.

Obviously, Bella also gets in on the wave-crashing action. Earlier this summer, the supermodel shared a selfie on Instagram captioned "Still on this jet ski," leading one to believe that her obsession may actually have surpassed her sister's. (And also leading one to believe, or at least hope, that she must have one of those waterproof iPhones).

And of course it's not just the Hadid sisters who love the noisy nautical vehicles. Last summer, Emily Ratajkowski caught the attention of, well, everyone with a cheeky jet ski post of her own.

The summer before that, Hailey Bieber (she was a Baldwin back then, how time flies) and Kendall Jenner (also a horse girl) joined Hadid on the jet ski bandwagon. (It should be noted that this was probably part of the promotional shoot for the ill-fated Fyre Festival, but we were blissfully unaware of that at the time.)

Jenner even climbed aboard her jet ski for a bottle cap challenge—and started a little bit of drama by contributing to the problem of plastic in the ocean.

Meanwhile, Heidi Klum—a supermodel, but not a horse girl— and her husband Tom Kaulitz were spotted celebrating their honeymoon on a jet ski in Italy.

And even some non-models have now been spotting jetting around. None other than Britney Spears hopped on a jet ski during her vacation with her boyfriend Sam Asghari earlier this summer. She is neither horse girl nor supermodel, but she is a pop culture icon who also happens to be an arbiter of Instagram trends to some degree. (OOTD would be nothing without her "runway series" and Spears has also taken gym selfies to the next level on the gram).

So what is the root of this trend? Who pioneered the "horse girl on a jet ski" genre in the first place? It probably started with Pamela Anderson.

Pamela Anderson, lover of animals.

Amy Graves/Getty Images

Pamela Anderson, lover of jet skis.

John M. Heller/Getty Images

Regardless of who started the movement, it makes sense that models who love to ride horses would also love to ride jet skis. Both activities require the ability to steer and hold your balance (and should require a helmet, too). Both can also be quite dangerous, but thankfully the celebrity horse girls can bring their equestrian expertise to the mechanical horse of the sea: the jet ski.

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